华师题库《数学建模》
华东师范大学第二届数学建模竞赛赛题
华东师范大学第二届数学建模竞赛赛题(2005. 5)为迎接2010年世博会的召开,设想在上海东方明珠电视塔内标出上海到世界35个大城市之间的距离. 这些大城市(按英语字典序排)是:1阿姆斯特丹2安卡拉3雅典4奥克兰5曼谷(最短距离)6巴萨罗那7北京8柏林9布鲁塞尔 10布达佩斯11开罗 12哥本哈根 13哈瓦那14赫尔辛基15香港16约翰内斯堡 17吉隆坡 18伦敦 19澳门 20墨西哥城21莫斯科 22新德里 23纽约 24奥斯陆 25巴黎26罗马 27斯德哥尔摩28悉尼 29台北 30东京31多伦多 32维也纳 33华沙 34惠灵顿 35苏黎世1. 计算上海市到以上各大城市间的距离(最短连线的长度),并填在以上表格的空格内(数值单位为千米,舍入到千米).2. 分别求出从上海到北京、伦敦、莫斯科、纽约、巴黎这五条最短路线上所经过(或最近)的其他一个大城市的名称(英文名或中文名皆可)、经纬度(单位度.分)、离开最短路线的距离(数值单位为千米,舍入到0.1千米),最短路线上与最近大城市距离最近的点的经纬度,(数值单位:度.分,舍入到分)并填入以下表格:北京伦敦莫斯科纽约巴黎(城市名)(城市经纬度)(距离)(最短线上点)注:1. 已知地球的平均半径为R = 6371千米.2. 大城市的范围及其经纬度见下表城市 纬度 度 分 经度 度 分(纬度中负号表示南纬, 经度中负号表示西经) Amsterdam, 52 22 4 53 (1)Ankara, 39 55 32 55 (2)Athens, 37 58 23 43 (3)Auckland, -36 52 174 45 (4)Bangkok, 13 45 100 30 (5)Barcelona, 41 23 2 9 (6)Beijing, 39 55 116 25 (7)Berlin, 52 30 13 25 (8)Brussels, 50 52 4 22 (9)Budapest, 47 30 19 5 (10)Cairo, 30 2 31 21 (11)Copenhagen, 55 40 12 34 (12)Havana, 23 8 -82 23 (13)Helsinki, 60 10 25 0 (14)Hong Kong, 22 20 114 11 (15)Johannesburg, -26 12 28 4 (16)Kuala Lumpur, 3 8 101 42 (17)London, 51 32 -0 5 (18)Macao, 22 13 113.36 (19)Mexico City, 19 26 -99 7 (20)Moscow, 55 45 37 36 (21)New Delhi, 28 35 77 12 (22)New York 40 47 -73 58 (23)Oslo, 59 57 10 42 (24)Paris, 48 48 2 20 (25)Rome, 41 54 12 27 (26)Stockholm, 59 17 18 3 (27)Sydney, -34 0 151 0 (28)Taipei, 25 05 121 32 (29)Tokyo, 35 40 139 45 (30)Toronto, 43 39 -79 23 (31)Vienna, 48 14 16 20 (32)Warsaw, 52 14 21 0 (33)Wellington, -41 17 174 47 (34)Zürich, 47 21 8 31 (35)Shanghai, 31 10 121 28 (36)(以上括号中的数字是题目中城市的编号, 以下是其他城市的纬度和经度)城市 纬度 度 分 经度 度 分 BRISBANE, -27 28 153 02 CANBERRA, -35 17 149 08 DARWIN, -12 28 130 50 DERBY, -17 19 123 38 NADI, -17 47 177 29 NEWMAN, -23 20 119 34 PERTH, -31 56 115 50 TOWNSVILLE, -19 13 146 48 BANGALORE, 12 58 77 35 BOMBAY, 18 56 -74 35 CALCUTTA, 22 30 88 20 COLOMBO, 6 55 79 52 DELHI, 28 40 77 14 HANOI, 21 01 105 52 HARBIN, 45 45 126 41 城市 纬度 度 分 经度 度 分 JINAN, 36 41 117 00 HO CHI MINH, 10 46 106 43 ISLAMABAD, 33 40 73 08 JAKARTA, -6 08 106 45 KAGOSHIMA, 31 37 130 32 KANDLA, 23 03 70 11 KARACHI, 24 51 67 02 KATHMANDU, 27 42 85 19 GUNUNGSITOLI, -6 03 116 32 KOTA, 2 33 102 10 KUALA LUMPUR, 3 08 101 42 KUNMING, 25 04 102 41 MALANG, -7 59 112 45 MANDALAY, 21 57 96 04 MANILA, 14 35 120 59NAGPUR, 21 10 79 12 PADANG, -6 12 120 27 PALU, -8 19 121 44 PENANG, 5 30 100 28 PONTIANAK, -0 05 109 16 RANGOON, 16 47 96 10 SAPPORO, 43 05 141 21 SEOUL, 37 30 127 00 SINGAPORE 1 18 103 50 SORONG, -0 50 131 17 THIMBU, 27 32 89 43 TONHIL, 46 19 93 54 ULAANBAATAR, 47 54 106 52 URUMQI, 43 43 87 38 WUHAN, 30 35 108 54 XIAN, 34 16 108 54 YUMEN, 39 54 97 43 ANADYR, 64 50 177 50 ARKHANGELSK, 64 32 40 40 ASHKHABAD, 37 58 58 24 BAKU, 40 22 49 53 BARNAUL, 53 21 83 45 CHITA, 52 03 113 35 IGARKA, 67 31 86 33 INARIGDA, 63 15 107 40 KIEV, 50 25 133 43 KRASNODAR, 45 02 39 00 MAGDAGACHI, 53 27 125 44 OKHOTSK, 59 20 143 15 PERM, 58 01 56 10 PETROPAVLOVSK, 54 53 69 13 TASHKENT, 41 16 69 13 TULUN, 54 32 100 35 VANINO, 49 05 140 14 VLADIVOSTOK, 43 09 131 53 VORKUTA, 67 27 64 00 YAKUTSK, 62 10 129 50 KUWAIT, 29 20 48 00 RUH RIYADH, 24 39 46 46 BAGHDAD, 33 20 44 26 HALAB, 36 14 37 10 HERAT, 34 20 62 12 JERUSALEM, 31 47 35 13 KABUL, 34 31 69 12 MASHAD, 36 16 59 34 NAZWA, 22 56 57 33 SALALAH, 17 00 54 04 SANAA, 15 24 44 14 SHIRAZ, 29 38 52 34 TABRIZ, 38 05 46 18 TARIM, 16 08 45 58 TEHRAN, 35 40 51 26 ABIDJAN, 5 19 -0 05 ALGIERS, 36 50 3 00 ANTANANARIVO, -18 52 47 30 ASWAN, 24 05 32 56 BAMAKO, 12 39 -8 00 BENGHAZI, 32 07 20 04 BANGUI, 4 22 18 35 BEIRA, -19 49 34 52 CAPETOWN, -35 55 18 22 DAKAR, 14 40 17 26 FREETOWN, 8 30 -13 15 HARARE, -17 50 31 30 KABWE, -14 29 28 25 KAMPALA, 0 19 35 25 KANO, 12 00 8 31 KHARTOUM, 15 36 32 32 KINSHASA, -4 18 15 18 KISANGANI, 0 33 25 14 LOS LAGOS, 6 27 3 24 LOBITO, -12 20 13 34 LUBUMBASHI, -11 41 27 29 LUDERITZ, -26 38 15 10 LUZAMBA, -4 59 23 26 MAPUTO, -25 58 32 35 MASERU, -29 19 27 29 MOGADISHU, 2 02 45 21 MONROVIA, 6 18 -10 47 MWANZA, -7 51 26 43 NAIROBI, -1 17 36 49 NAMIBE, -15 10 12 09 NOUAKCHOTT, 18 09 -15 58 OUAGADOUGOU, 12 22 -1 31 POINTE NOIRE, -4 46 11 53 SEBHA, 27 02 14 26 SERONERA, -22 25 26 44 TOMBOUCTOU, 16 49 -2 59TRIPOLI, 32 54 13 11TSUMEB, -19 13 17 42TUNIS, 36 48 10 11WINHOEK, -22 34 17 06YAOUNDE, 3 52 11 31ZANZIBAR, -6 10 39 20BERNE, 46 57 7 26BORDEAUX, 44 50 -0 34BUCHAREST, 44 26 26 06GDANSK, 54 23 18 40GLASGOW, 55 53 -4 15HAMBURG, 53 33 9 59ISTANBUL, 41 01 28 58LONGYEARBYEN, 78 12 15 40MADRID, 40 24 -3 41MILAN, 45 27 9 17NAPLES, 40 51 14 17NICE, 43 42 7 15NUUGAATSIAQ, 71 30 -53 00 REYKJAVIK, 64 09 -21 51 SCORESBYSUND, 70 30 -22 00 STENSELE, 65 05 17 10 TORSHAVN 62 02 -6 47 TRABZON, 41 00 39 43 VARDOE, 60 16 20 20 ANTOFAGASTA, -23 40 -70 23 AREQUIPA, -16 25 -71 32 BELEM, -1 27 -48 29 BOGOTA, 4 36 -74 05 BRASILIA, -15 47 -47 55 CARACAS, 10 30 -66 56 CAYENNE, 4 56 -52 20 CHIHUAHUA, 28 40 -106 06 CHURCHILL, 58 45 -94 00 COMODORO, -45 50 -67 30 COPPERMINE, 67 49 115 21 CORDOBA, 18 55 -96 55 CUIABA, -7 15 -58 25 GEORGETOWN, 6 48 -58 10 GUADALAJARA, 20 40 -103 20 GUANTANAMO, 20 09 -75 14 GUATEMALA CITY, 14 38 -90 31 GUAYAQUIL, -2 10 -79 50 ILHEUS, -14 50 -39 06IQUITOS, -3 51 -73 13 LABRADOR CITY, 52 56 -66 52 LIMA, -12 03 -77 03 MANAGUA, 12 06 -86 18 MANAUS, -3 06 -60 00 MERIDA, 8 24 -71 08 MONTEVIDEO, -34 53 -56 11 PANAMA CITY, 8 58 -79 32 QUEBEC, 46 50 -71 15 RIO DE JANEIRO, -22 54 -43 14 TIJUANA, 32 32 -117 01 VALPARAISO, -21 16 -50 54 VANCOUVER, 49 16 -123 07 VERACRUZ, 19 12 -96 08 WINNIPEG, 49 53 -97 09 SAMOA, -14 20 -170 00 HONOLULU, 21 18 -157 51。
数学建模知识竞赛题库
4.世界上面值最高的邮票是匈牙利五百亿彭哥,它的图案是 BA.猫B.飞鸽C.海鸥D.鹰6.MATLAB 使用三维向量[R G B]来表示一种颜色,则黑色为( D )A. [1 0 1]B. [1 1 1]C. [0 0 1]D. [0 0 0]9 我国第一个获得世界冠军的是谁? CA 吴传玉B 郑凤荣C 荣国团D 陈镜开10.我国最早在奥运会上获得金牌的是哪位运动员? BA.李宁B.许海峰C.高凤莲D.吴佳怩B 分子结构图11.围棋共有多少个棋子? BA.360B.361C.362D.36512 下列属于物理模型的是:AA 水箱中的舰艇B 分子结构图C 火箭模型D 电路图13 名言:生命在于运动是谁说的? CA.车尔尼夫斯基B.普希金C.伏尔泰D.契诃夫14.饱食后不宜剧烈运动是因为 BA.会得阑尾炎B.有障消化C.导致神经衰弱D.呕吐15、 MATLAB 软件中,把二维矩阵按一维方式寻址时的寻址访问是按( B )优先的。
A.行B.列C.对角线D.左上角16 红军长征中,哪次战役最突出反应毛泽东的军事思想和指挥才 ?AA.四渡赤水B.抢渡大渡河C.飞夺泸定桥D.直罗镇战役17 色盲患者最普遍的不易分辨的颜色是什么? AA. 红绿B.蓝绿C.红蓝D.绿蓝18 下列哪种症状是没有理由遗传的?A. 精神分裂症B.近视C.糖尿病D. 口吃19 下面哪个变量是正无穷大变量?( A )A. InfB. NaNC. realmaxD. realmin20 泼水节是我国哪个少数民族的节日? DA.彝族B.回族C.壮族D.傣族21 被称为画圣的是古代哪位画家 ?AA 吴道子 B.顾恺之 C.韩干 D.张择端22 我国第一部有声影片是 AA. 日本B.美国C.德国D.英国A 四郎探母 B.定军山 C.林则徐 D.玉人何处23 奔驰原产于哪国?CA 美国 B. 日本 C.德国 D.英国24.菲利浦电器是哪一国家的产品? BA. 日本B.美国C.德国D.英国25 奥运会每四年举办一次,为期不超过多少天? BA.14 天B.16 天C.20 天D.21 天26.看鱼鳞能识鱼鳞,鱼鳞上的一圈代表? AA.半岁B.一岁C.一岁半D.两岁27.世界上最长的动物是哪一种? BA.鲸鱼B.水母C.恐龙D.大象28.山东山西中的山是指?BA.泰山B.太行山C.沂蒙山D.恒山29 坦克是哪个国家发明的? AA 英国 B.德国 C.美国 D.法国30 我军三大纪律,八项注意中三大纪律不包括? A不贪污受贿 B.一切听从指挥 C.不拿群众一针一线 D.一切缴获要归公31 雨后彩虹,美丽可目,但在 1928 年 1 月 7 日,由马德拉岛到开普敦的海面上,出现了一道奇特的彩虹,在能见度很差的雾霭中有一光晕,晕环下部似乎能触及船侧,你知道这道彩虹成什么颜色吗? DA.红色B.蓝白色C.蓝色D. 白色32. “牛郎织女”的故事是众口皆碑的神话传说,你知道牛郎星属于什么星座吗? BA.天琴座B.天鹰座C.金牛座D.狮子座33 世界上曾有六次截流,中国就有三次,都在长江上,其中有两次是长江三峡截流,另一次是哪项工程? CA. 都江堰B.黄河C.葛洲坝D.钱塘江34唐代诗人有称诗“圣”的杜甫诗“仙”的李白等,你可知道被人颂称诗“魔”的是谁? AA. 白居易B.王维C.刘禹锡D.李商隐35 “君子之交淡如水,小人之交甘若醴”出自下列哪部作品? BA.老子B.庄子C.论语D.史记36.在 Word2003 文档中,对图片设置下列哪种环绕方式后,可以形成水印效果。
华中师大《高等数学》练习测试题库及答案(可编辑)
华中师大《高等数学》练习测试题库及答案华中师范大学网络教育《高等数学》练习测试题库及答案一.选择题1.函数y 是()A.偶函数B.奇函数 C 单调函数D 无界函数2.设fsincosx+1,则fx为()A 2x-2B 2-2xC 1+xD 1-x3.下列数列为单调递增数列的有()A.0.9 ,0.99,0.999,0.9999B.,,,C.fn,其中fnD.4.数列有界是数列收敛的()A.充分条件B. 必要条件C.充要条件D 既非充分也非必要5.下列命题正确的是( )A.发散数列必无界B.两无界数列之和必无界C.两发散数列之和必发散D.两收敛数列之和必收敛6.()A.1B.0C.2D.1/27.设e 则kA.1B.2C.6D.1/68.当x1时,下列与无穷小(x-1)等价的无穷小是( )A.x-1B. x-1C.x-1D.sinx-19.fx在点xx0处有定义是fx在xx0处连续的()A.必要条件B.充分条件C.充分必要条件D.无关条件10、当|x|1时,y ()A、是连续的B、无界函数C、有最大值与最小值D、无最小值11、设函数f(x)(1-x)cotx要使f(x)在点:x0连续,则应补充定义f(0)为()A、 B、e C、-eD、-e-112、下列有跳跃间断点x0的函数为()A、 xarctan1/xB、arctan1/xC、tan1/xD、cos1/x13、设fx在点x0连续,gx在点x0不连续,则下列结论成立是( )A、fx+gx在点x0 必不连续B、fx×gx在点x0必不连续须有C、复合函数f[gx]在点x0必不连续D、在点x0必不连续14、设fx 在区间- ∞,+ ∞上连续,且fx0,则a,b满足()A、a>0,b>0B、a>0,b<0C、a<0,b>0D、a<0,b<015、若函数fx在点x0连续,则下列复合函数在x0也连续的有( )A、B、 C、tan[fx]D、f[fx]16、函数fxtanx能取最小最大值的区间是下列区间中的( )A、[0,л]B、(0,л)C、[-л/4,л/4]D、(-л/4,л/4)17、在闭区间[a ,b]上连续是函数fx有界的()A、充分条件B、必要条件C、充要条件D、无关条件18、fafb <0是在[a,b]上连续的函fx数在(a,b)内取零值的( )A、充分条件B、必要条件C、充要条件D、无关条件19、下列函数中能在区间0,1内取零值的有( )A、fxx+1B、fxx-1C、fxx2-1D、fx5x4-4x+120、曲线yx2在x1处的切线斜率为( )A、k0B、k1C、k2D、-1/221、若直线yx与对数曲线ylogx相切,则( )A、eB、1/eC、exD、e1/e22、曲线ylnx平行于直线x-y+10的法线方程是( )A、x-y-10B、x-y+3e-20C、x-y-3e-20D、-x-y+3e-2023、设直线yx+a与曲线y2arctanx相切,则a( )A、±1B、±л/2C、±л/2+1D、±л/2-124、设fx为可导的奇函数,且f`x0a, 则f`-x0( )A、aB、-aC、|a|D、025、设y? ,则y’|x0( )A、-1/2B、1/2C、-1D、026、设ycossinx,则y’|x0()A、-1B、0C、1D、不存在27、设yfx ?1+X,yf[fx],则y’|x0( )A、0B、1/ ?2C、1D、 ?228、已知ysinx,则y10( )A、sinxB、cosxC、-sinxD、-cosx29、已知yx?x,则y10( )A、-1/x9B、1/ x9C、8.1/x9D、 -8.1/x930、若函数fxxsin|x|,则( )A、f``0不存在B、f``00C、f``0 ∞D、 f``0 л31、设函数yyfx在[0,л]内由方程x+cosx+y0所确定,则|dy/dx|x0()A、-1B、0C、л/2D、 232、圆x2cosθ,y2sinθ上相应于θл/4处的切线斜率,K( )A、-1B、0C、1D、 233、函数fx在点x0连续是函数fx在x0可微的( )A、充分条件B、必要条件C、充要条件D、无关条件34、函数fx在点x0可导是函数fx在x0可微的( )A、充分条件B、必要条件C、充要条件D、无关条件35、函数fx|x|在x0的微分是( )A、0B、-dxC、dxD、不存在36、极限的未定式类型是( )A、0/0型B、∞/∞型C、∞ -∞D、∞型37、极限的未定式类型是()A、00型B、0/0型C、1∞型D、∞0型38、极限( )A、0B、1C、2D、不存在39、xx0时,n阶泰勒公式的余项Rnx是较xx0 的( )A、(n+1)阶无穷小B、n阶无穷小C、同阶无穷小D、高阶无穷小40、若函数fx在[0, +∞]内可导,且f`x >0,xf0 <0则fx在[0,+ ∞]内有()A、唯一的零点B、至少存在有一个零点C、没有零点D、不能确定有无零点41、曲线yx2-4x+3的顶点处的曲率为( )A、2B、1/2C、1D、042、抛物线y4x-x2在它的顶点处的曲率半径为( ) A、0B、1/2 C、1D、243、若函数fx在(a,b)内存在原函数,则原函数有()A、一个B、两个C、无穷多个D、都不对44、若∫fxdx2ex/2+C( )A、2ex/2B、4 ex/2C、ex/2 +CD、ex/245、∫xe-xdx ( D )A、xe-x -e-x +CB、-xe-x+e-x +CC、xe-x +e-x +CD、-xe-x -e-x +C46、设P(X)为多项式,为自然数,则∫Pxx-1-ndx( )A、不含有对数函数B、含有反三角函数C、一定是初等函数D、一定是有理函数47、∫-10|3x+1|dx( )A、5/6B、1/2C、-1/2D、148、两椭圆曲线x2/4+y21及x-12/9+y2/41之间所围的平面图形面积等于( )A、лB、2лC、4лD、6л49、曲线yx2-2x与x轴所围平面图形绕轴旋转而成的旋转体体积是( )A、лB、6л/15C、16л/15D、32л/1550、点(1,0,-1)与(0,-1,1)之间的距离为( )A、B、2 C、31/2 D、 21/251、设曲面方程(P,Q)则用下列平面去截曲面,截线为抛物线的平面是( )A、Z4B、Z0C、Z-2D、x252、平面xa截曲面x2/a2+y2/b2-z2/c21所得截线为( )A、椭圆B、双曲线C、抛物线D、两相交直线53、方程0所表示的图形为( )A、原点(0,0,0)B、三坐标轴C、三坐标轴D、曲面,但不可能为平面54、方程3x2+3y2-z20表示旋转曲面,它的旋转轴是( )A、X轴B、Y轴C、Z轴D、任一条直线55、方程3x2-y2-2z21所确定的曲面是( )A、双叶双曲面B、单叶双曲面C、椭圆抛物面D、圆锥曲面56、设函数f(x)=—— ,g(x)=1-x,则f[g(x)]= ( )x 1 1 1A.1- ——B.1+ ——C. ————D.x x x 1- x 157、x→0 时,xsin——+1 是 ( ) x A.无穷大量 B.无穷小量 C.有界变量D.无界变量58、方程2x+3y=1在空间表示的图形是 ( ) A.平行于xoy面的平面 B.平行于oz轴的平面 C.过oz轴的平面 D.直线59、下列函数中为偶函数的是( ) A.y=e^x B.y=x^3+1C.y=x^3cosxD.y=ln│x│60、设f(x)在(a,b)可导,a〈x_1〈x_2〈b,则至少有一点ζ∈(a,b)使( )A.f(b)-f(a)=f'(ζ)(b-a)B.f(b)-f(a)=f'(ζ)(x2-x1)C.f(x2)-f(x1)=f'(ζ)(b-a)D.f(x2)-f(x1)=f'(ζ)(x2-x1)61、设f(X)在 X=Xo 的左右导数存在且相等是f(X)在 X=Xo 可导的 ( ) A.充分必要的条件 B.必要非充分的条件 C.必要且充分的条件 D既非必要又非充分的条件二、填空题1、求极限 x2+2x+5/x2+1( )2、求极限 [x3-3x+1/x-4+1]( )3、求极限x-2/x+21/2( )4、求极限 [x/x+1]x( )5、求极限 1-x1/x ( )6、已知ysinx-cosx,求y`|xл/6()7、已知ρψsinψ+cosψ/2,求dρ/dψ| ψл/6( )8、已知fx3/5x+x2/5,求f`0( )9、设直线yx+a与曲线y2arctanx相切,则a( )10、函数yx2-2x+3的极值是y1()11、函数y2x3极小值与极大值分别是( )12、函数yx2-2x-1的最小值为()13、函数y2x-5x2的最大值为( )14、函数fxx2e-x在[-1,1]上的最小值为( )15、点(0,1)是曲线yax3+bx2+c的拐点,则有b()c()16、∫xx1/2dx ( )17、若F`xfx,则∫dFx ( )18、若∫fxdxx2e2x+c,则fx19、d/dx∫abarctantdt()20、已知函数fx在点x0连续, 则a( )21、∫02x2+1/x4dx( )22、∫49 x1/21+x1/2dx( )23、∫031/2a dx/a2+x2()24、∫01 dx/4-x21/2()25、∫л/3лsinл/3+xdx( )26、∫49 x1/21+x1/2dx27、∫49 x1/21+x1/2dx( )28、∫49 x1/21+x1/2dx( )29、∫49 x1/21+x1/2dx( )30、∫49 x1/21+x1/2dx( )31、∫49 x1/21+x1/2dx( )32、∫49 x1/21+x1/2dx( )33、满足不等式|x-2|<1的X所在区间为34、设fx [x] +1,则f(л+10)()35、函数Y|sinx|的周期是 ()36、ysinx,ycosx直线x0,xл/2所围成的面积是 ()37、 y3-2x-x2与x轴所围成图形的面积是 ( )38、心形线ra1+cosθ的全长为( )39、三点(1,1,2),(-1,1,2),(0,0,2)构成的三角形为 ( )40、一动点与两定点(2,3,1)和(4,5,6)等距离,则该点的轨迹方程是 ()41、求过点(3,0,-1),且与平面3x-7y+5z-120平行的平面方程是()42、求三平面x+3y+z1,2x-y-z0,-x+2y+2z0的交点是43、求平行于xoz面且经过(2,-5,3)的平面方程是 ( )44、通过Z轴和点(-3,1,-2)的平面方程是 ( )45、平行于X轴且经过两点(4,0,-2)和(5,1,7)的平面方程是( )46、函数y=arcsin√1-x^2 + ——————的定义域为_________ √1-x^2_______________。
《数学建模》试卷及答案_高中数学选择性必修第三册_人教A版_2024-2025学年
《数学建模》试卷(答案在后面)一、单选题(本大题有8小题,每小题5分,共40分)1、一个长方体的长、宽、高分别为3, 4, 5,求其体积。
A、60B、20C、12D、92、在建立数学模型时,以下哪种方法通常用于确定数学模型的形式?()A. 观察法B. 理论分析法C. 统计分析法D. 模拟法3、在建立数学模型的过程中,以下哪个步骤不是必须的?A、收集数据B、提出假设C、建立方程D、验证模型4、某中学数学建模小组对某一社区的家用车流量进行了模型分析。
若该社区每小)],其中(t)时通过的家用车流量(单位:辆/h)满足以下关系:[f(t)=100+5sin(πt12(单位:小时)是从12:00开始的时间,那么该社区15:00至16:00之间通过的家用车流量估计为多少辆?A、105B、103C、101D、995、在数学建模过程中,以下哪种方法被用于解决实际问题中的系统优化问题?A. 逻辑推理法B. 据统计法C. 线性规划法D. 递归分析法6、某工厂生产某种产品,已知每生产x件产品,需要原材料费1000元,生产成本每件30元。
若工厂以每件50元售出,问工厂至少要生产多少件产品才能保证不亏损?A)25件B)30件C)35件D)40件7、(2019·江苏卷)某校学生在校参加社团活动的频率与每周用于社团活动的平均时间如下表所示:次数1次2次3次4次5次及5次以上时间(小时) 5.5810.51317根据上述数据,若该生下周参加1次社团活动,则其下周用于社团活动的平均时间为 ______ 小时。
A. 9B. 10C. 11D. 128、某城市出租车计费规则如下:起步价为10元,包含前3公里;超过3公里后,每增加1公里加收2元,不足1公里按1公里计算。
若乘客乘坐出租车行驶了x公里(x > 3),则乘客应付的车费y(元)与行驶距离x(公里)之间的函数关系式为:A. y = 10 + 2(x - 3)B. y = 10 + 2xC. y = 2x - 6D. y = 12 + 2(x - 3)二、多选题(本大题有3小题,每小题6分,共18分)1、(5分)以下关于数学建模的说法中,正确的是:A. 数学建模是一种将实际问题转化为数学问题的过程B. 数学建模只适用于数学专业,其他专业无需涉及C. 数学建模需要运用数学知识、计算机技术以及实际应用背景D. 数学建模的目的是为了找到问题的最优解2、某市计划在城市中心建立一个大型公园,以提高市民的生活质量。
(完整版)数学建模模拟试题及答案
数学建模模拟试题及答案一、填空题(每题 5 分,共 20 分)1.一个连通图能够一笔画出的充分必要条件是.2. 设银行的年利率为 0.2,则五年后的一百万元相当于现在的万元.3. 在夏季博览会上,商人预测每天冰淇淋销量N 将和下列因素有关:(1) 参加展览会的人数n; (2)气温T 超过10o C;(3)冰淇淋的售价p .由此建立的冰淇淋销量的比例模型应为 .4. 如图一是一个邮路,邮递员从邮局 A 出发走遍所有 A长方形街路后再返回邮局 .若每个小长方形街路的边长横向均为 1km,纵向均为 2km,则他至少要走 km .二、分析判断题(每题 10 分,共 20 分)1. 有一大堆油腻的盘子和一盆热的洗涤剂水。
为尽量图一多洗干净盘子,有哪些因素应予以考虑?试至少列出四种。
2. 某种疾病每年新发生 1000 例,患者中有一半当年可治愈 .若 2000 年底时有1200 个病人,到 2005 年将会出现什么结果?有人说,无论多少年过去,患者人数只是趋向 2000 人,但不会达到 2000 人,试判断这个说法的正确性 .三、计算题(每题 20 分,共 40 分)1. 某工厂计划用两种原材料A, B 生产甲、乙两种产品,两种原材料的最高供应量依次为 22 和 20 个单位;每单位产品甲需用两种原材料依次为 1 、1 个单位,产值为 3 (百元);乙的需要量依次为 3、1 个单位,产值为 9 (百元);又根据市场预测,产品乙的市场需求量最多为 6 个单位,而甲、乙两种产品的需求比不超过 5: 2,试建立线性规划模型以求一个生产方案,使得总产值达到最大,并由此回答:(1) 最优生产方案是否具有可选择余地?若有请至少给出两个,否则说明理由 .(2) 原材料的利用情况 .2. 两个水厂A1 , A2将自来水供应三个小区B1 , B2 , B3 , 每天各水厂的供应量与各小区的需求量以及各水厂调运到各小区的供水单价见下表 .试安排供水方案,使总供水费最小?四、 综合应用题(本题 20 分)某水库建有 10 个泄洪闸,现在水库的水位已经超过安全线,上游河水还在不断地流入 水库.为了防洪,须调节泄洪速度 .经测算,若打开一个泄洪闸, 30 个小时水位降至安全线, 若打开两个泄洪闸, 10 个小时水位降落至安全线 .现在,抗洪指挥部要求在 3 个小时内将水 位降至安全线以下,问至少要同时打开几个闸门?试组建数学模型给予解决 .注:本题要求按照五步建模法给出全过程 .小区 单价/元水厂A1A供应量 / t170B34B11 07 1B26数学建模 06 春试题模拟试题参考解答一、填空题(每题 5 分,共 20 分)1. 奇数顶点个数是 0 或 2;2. 约 40.1876 ;3. N = Kn(T10) / p, (T > 10 0 C), K 是比例常数; 4. 42.二、分析判断题(每题 10 分,共 20 分)1. 解: 问题与盘子、水和温度等因素直接相关,故有相关因素:盘子的油腻程度,盘子的温度,盘子的尺寸大小;洗涤剂水的温度、浓度; 刷洗地点 的温度等.注:列出的因素不足四个,每缺一个扣 2.5 分。
2010年华南师范大学第九届数学建模竞赛题目
2010年华南师范大学第九届数学建模竞赛题目(请先阅读“华南师范大学数学建模竞赛论文格式规范”)A题疾走食肉恐龙问题有一种疾走食肉恐龙(Velociraptor mongoliensis)生活在距今约7500万年前的白垩纪晚期。
古生物学家认为它是顽强的捕猎者,可能成群地、并且一对一对地进行捕猎。
可惜不可能像观察现代的食肉哺乳动物那样观察疾走食肉恐龙在野外的捕猎行为。
古生物学家请你们队帮助对疾走食肉恐龙的捕猎行为进行建模。
古生物学家希望将你们的结果与研究狮子、老虎以及类似的食肉动物的生物学家所报告的野外调查数据进行比较。
成年的疾走食肉恐龙一般身长3米,髋高0.5米,重约45公斤,据估计奔跑非常快,以每小时60公里的速度可持续奔跑约15秒钟,但是在以这样的速度冲刺之后,它需要停下来,通过在肌肉里增加乳酸使得体力恢复。
假定疾走食肉恐龙捕食与自己体型几乎相同的一种双足食草恐龙(Thescelosaurus neglectus)。
对化石的生命力学分析揭示双足食草恐龙能以每小时50公里的速度长时间奔跑。
第一问:假设疾走食肉恐龙是孤单的捕猎者,建立数学模型,描述一只疾走食肉恐龙潜随和追猎一只双足食草恐龙的捕猎策略,以及被捕食者的逃避策略。
假设双足食草恐龙在相距15米之内一定能觉察到疾走食肉恐龙,依赖于环境和气候条件可以在更大的范围内(一直到50米)觉察到。
另外,由于身体结构和力量的缘故,疾走食肉恐龙在全速奔跑时的转弯半径是有限的,据估计,该半径是髋高的三倍。
而双足食草恐龙却极其灵活,转弯半径仅为0.5米。
第二问:更符合实际地假设疾走食肉恐龙成对地去捕猎,建立新的模型,描述两只疾走食肉恐龙潜随和追猎一只双足食草恐龙的捕猎策略,以及被捕食者的逃避策略。
继续使用第一问给出的其他假设。
组委会对A题的说明:本题来自美国数学建模竞赛,在书刊、网络可以找到一些优秀论文或解法介绍,请同学们引用这些资料时务必给出参考文献标注,否则会被评委认定为抄袭而失去评奖资格。
数学建模试卷及参考答案
数学建模试卷及参考答案数学建模试卷及参考答案⼀.概念题(共3⼩题,每⼩题5分,本⼤题共15分)1、⼀般情况下,建⽴数学模型要经过哪些步骤?(5分)答:数学建模的⼀般步骤包括:模型准备、模型假设、模型构成、模型求解、模型分析、模型检验、模型应⽤。
2、学习数学建模应注意培养哪⼏个能⼒?(5分)答:观察⼒、联想⼒、洞察⼒、计算机应⽤能⼒。
3、⼈⼯神经⽹络⽅法有什么特点?(5分)答:(1)可处理⾮线性;(2)并⾏结构.;(3)具有学习和记忆能⼒;(4)对数据的可容性⼤;(5)神经⽹络可以⽤⼤规模集成电路来实现。
⼆、模型求证题(共2⼩题,每⼩题10分,本⼤题共20分)1、某⼈早8:00从⼭下旅店出发,沿⼀条路径上⼭,下午5:00到达⼭顶并留宿.次⽇早8:00沿同⼀路径下⼭,下午5:00回到旅店.证明:这⼈必在2天中同⼀时刻经过路途中某⼀地点(15分) 证明:记出发时刻为,到达⽬的时刻为,从旅店到⼭顶的路程为s.设某⼈上⼭路径的运动⽅程为f(t), 下⼭运动⽅程为g(t)是⼀天内时刻变量,则f(t)(t)在[]是连续函数。
作辅助函数F(t)(t)(t),它也是连续的,则由f(a)=0(b)>0和g(a)>0(b)=0,可知F (a )<0, F(b)>0, 由介值定理知存在t0属于()使F(t0)=0, 即f(t0)(t0) 。
2、三名商⼈各带⼀个随从乘船过河,⼀只⼩船只能容纳⼆⼈,由他们⾃⼰划⾏,随从们秘约,在河的任⼀岸,⼀旦随从的⼈数⽐商⼈多,就杀⼈越货,但是如何乘船渡河的⼤权掌握在商⼈们⼿中,商⼈们怎样才能安全渡河呢?(15分) 解:模型构成记第k 次渡河前此岸的商⼈数为k x ,随从数为k y ,1,2,........,k x ,k y =0,1,2,3。
将⼆维向量k s =(k x ,k y )定义为状态。
安全渡河条件下的状态集合称为允许状态集合,记做S 。
()}{2,1;3,2,1,0,3;3,2,1,0,0|,======y x y x y x y x (3分)记第k 次渡船上的商⼈数为k u 随从数为k v 将⼆维向量k d =(k u ,k v )定义为决策。
华师数学建模考试资料
数学建模名词解释:一阶差分方程标准答案:2.第9题名词解释:数学模型标准答案:数学模型(Mathematical Model)是由数字、字母或者其他数学符号组成的,描述现实对象数量规律的数学公式、图形或算法.3.第10题名词解释:二阶差分方程4.第15题名词解释:(1)线性规划模型;(2)线性规划模型的可行域;(3)线性规划模型的最优解和最优值;(4)不可行的线性规划模型;(5)无界的线性规划模型.标准答案:5.第4题标准答案:6.第11题司机在驾驶过程中遇到突发事件会紧急刹车,从司机决定刹车到车完全停住汽车行驶的距离称为刹车距离,车速越快,刹车距离越长. 请问刹车距离与车速之间具有怎样的数量关系7.第12题考虑弹簧-质量系统,收集弹簧伸长的长度与弹簧末端悬挂的质量的实验数据,记录在表1(单位省略). 请计算出伸长与质量的函数关系的经验公式.表1 弹簧伸长和质量的测量数据伸长 5.675 6.5007.2508.0008.750标准答案:8.第14题(接续47 酶促反应(1)和48酶促反应(2))请分析Michaelis-Menten模型非线性拟合和线性化拟合的结果有何区别?原因是什么?标准答案:您的答案:题目分数:4.0此题得分:0.09.第1题阅读材料电声器材厂在生产扬声器的过程中,有一道重要的工序:使用AB胶粘合扬声器中的磁钢与夹板. 长期以来,由于对AB胶的用量没有一个确定的标准,经常出现用胶过多,胶水外溢;或用胶过少,产生脱胶,影响了产品质量. 表1是一些恰当用胶量的具体数据.2设自变量x为磁钢面积,因变量y为恰当用胶量,用以下MATLAB脚本做一元线性回归分析的计算:x=[11.0;19.4;26.2;46.6;56.6;67.2;125.2;189.0;247.1;443.4];y=[0.164;0.396;0.404;0.664;0.812;0.972;1.688;2.86;4.076;7.332];X=[ones(size(x)),x]; [b,bint,r,rint,stat]=regress(y,X)命令窗口显示的计算结果:b =-0.101210.016546bint =-0.24763 0.0452090.015728 0.017365r =0.08320.176210.071696-0.0058489-0.023312-0.038703-0.28239-0.166040.0886160.096575rint =-0.2348 0.4012-0.11393 0.46635-0.2522 0.39559-0.33976 0.32806-0.35828 0.31166-0.37408 0.29667-0.51782 -0.046954-0.46895 0.13686-0.2249 0.40213-0.077904 0.27105stat =0.99633 2174 4.948e-011 0.02121问题请将计算结果整理成表格,并进行分析.标准答案:10.第6题标准答案:您的答案:题目分数:5.0 此题得分:0.011.第7题标准答案:您的答案:题目分数:9.0 此题得分:0.012.第8题标准答案:您的答案:题目分数:8.0此题得分:0.013.第16题某营养师要为某个儿童预定午餐和晚餐,已知一个单位的午餐含12个单位的碳水化合物,6个单位蛋白质和6个单位的维生素C;一个单位的晚餐含8个单位的碳水化合物,6个单位的蛋白质和10个单位的维生素C. 另外,该儿童这两餐需要的营养中至少含64个单位的碳水化合物,42个单位的蛋白质和54个单位的维生素C. 如果一个单位的午餐、晚餐的费用分别是2.5元和4元,那么要满足上述的营养要求,并且花费最少,应当为该儿童分别预定多少个单位的午餐和晚餐?标准答案:您的答案:题目分数:8.0 此题得分:0.014.第2题标准答案:您的答案:题目分数:4.0此题得分:0.0教师未批改15.第5题写出以下公式:按照最小二乘法,由样本数据计算一元线性回归模型的回归系数的点估计.标准答案:您的答案:题目分数:5.0此题得分:0.0教师未批改16.第13题请概括数学软件MATLAB的特点。
华东师大数模第1章答案01~ch1_solutions
1. An automobile manufacturer makes a profit of $1,500 on the sale of a certain model. It is estimated that for every $100 of rebate, sales increase by 15%.(a) What amount of rebate will maximize profit? Use the five-step method, and model as a one-variable optimization problem.Step 1: Ask the question.Variables:r = rebate ($)s = number of cars soldP= profit ($)Assumptions:s= s_0 (1+0.15(r/100))P= (1500-r) ss>= 0 , 0<= r <=1500where the constant s_0 is the number of sales without any rebate Objective:Maximize P.Step 2: Select the modeling approach.We will model this problem as a one variable optimization problem. See text p. 6.Step 3: Formulate the model.Let x=r and y=P, and writey = f(x) = (1500-x) s_0 (1+0.15(x/100)).Our goal is to maximize f(x) over the interval [0, 1,500].Step 4: Solve the model.Compute f '(x) = 1500 s_0 (0.0015) + (-1) s_0 (1+0.15(x/100)) = 0 at x = 416.6667,f(x) = 1760.42 and since the graph of f(x) is a parabola we know this is the global maximum.Step 5: Answer the question.According to this model, the optimal policy is to offer a rebate of around $420, which should result in about a 17% increase in profits as compared to no rebate.(b) Compute the sensitivity of your answer to the 15% assumption. Consider both the amount of rebate and the resulting profit.Generalize the model from part (a) and lety = f(x) = (1500-x) s_0 (1+e x)where currently e = 0.0015. Compute thatf '(x) = 1500 s_0 e + (-1) s_0 (1+e x) = 0at x = 750-1/(2e). Then dx/de = 1/(2 e^2), and soS(x,e) = (dx/de) (e/x) = 1/(2*0.0015^2) (0.0015/416.6667) = 0.8so if the rebate is 10% more effective then we thought, then the optimal rebate will be 8% bigger. A similar computation yields S(y,e) = 0.38 so that if the rebate is 10% more effective than we thought, then our optimal profit will be 4% greater.(c) Suppose that rebates actually generate only a 10% increase in sales per $100. What is the effect? What if the response is somewhere between 10 and 15% per $100 of rebate?Using the results of part (b), if e decreases by 33% to 0.0010 then we expect the optimal rebate to decrease by (0.8) 33% = 27% to around $310. We would also expect profits to go down by (0.38) 33% = 13% to around $1530. A direct computation (solve the entire problem again using e=0.0010) yields a similar result: a 40% decrease in the optimal rebate (to $250) and an 11% decrease in profit (to 1562.50).(d) Under what circumstances would a rebate offer cause a reduction in profit?Using the sensitivity results of part (b), if every $100 of rebate results in a sales increase of less than 8.3% then the optimal policy is to offer no rebate. To see this, note that currently the optimal profit is 17% higher than with no rebate, and (0.38) 44.7% = 17%. The current rebate effectiveness is e = 0.0015 and so a 44.7% decrease yields 0.00083. Exact calculations yield a similar result: if every $100 of rebate results in a sales increase of less than 6.7% then the optimal policy is to offer no rebate. To see this, note that by the formula derived in part (b), the optimal rebate is x = 750-1/(2e), which decreases to zero as e decreases to 1/(2*750) = 0.00067.2. In the pig problem, perform a sensitivity analysis based on the cost per day of keeping the pig. Consider both the effect on the best time to sell and on the resulting profit. If a new feed costing 60 cents/day would let the pig grow at a rate of 7 lbs/day, would it be worth switching feed? What is the minimum improvement in growth rate that would make this new feed worthwhile?In this case we havey = f (x) = (0.65 - 0.01 x) (200 + 7 x) - 0.60 xand so f '(x) = (195 - 14 x) / 100 = 0 at around x = 13.9, f (x) = 143.58. This is the global maximum since f (x) is a parabola. Since this is considerably more than the old maximum of 133.20, it is worth while to switch to the new feed.More generally we havey = f (x) = (0.65 - 0.01 x) (200 + g x) - 0.60 xwhere currently g = 7. Compute that f '(x) = (65 (g - 4) - 2 g x) / 100 = 0 when x = 65 (g - 4) / (2 g)and substitute this back into the expression for y to obtainy = 13 (13 g^2 + 56 g + 208) / (16 g)which is equal to 133.20 when g = 5.26. Thus the new feed would be worth 60 cents per day as long as it produced a growth rate of at least 5.26 pounds per day.3. Reconsider the pig problem, of Example 1.1, but now assume that the price for pigs is starting to level off. Letp = 0.65 - 0.01t + 0.00004 t^2(4)represent the price for pigs (cents/lb) after t days.(a) Graph Eq. (4) along with our original price equation. Explain why our original price equation could be considered as an approximation to Eq. (4) for values of t near zero. The following graph shows the new, nonlinear price function along with the original, linear price function. The original equation is the tangent line to the new equation at t = 0, and so the original equation may be considered as an approximation of the new equation for values of t near zero.GRAPHING UTILITYp = 0.65 - 0.01t + 0.00004 t^2ptnew p(t)original p(t)(b) Find the best time to sell the pig. Use the five-step method, and model as a one-variable optimization problem.Step 1: Ask the question.Exactly the same as in the text p. 5, but now we assume p = 0.65 - 0.01 t + 0.00004 t^2. Step 2: Select the modeling approach.We will model this problem as a one variable optimization problem. See text p. 6. Step 3: Formulate the model.Let x=t and y=P, and writey = f(x) = (0.65 - 0.01 x + 0.00004 x^2) (200 + 5 x) - 0.45 x.Our goal is to maximize f(x) over the set of all x >= 0.Step 4: Solve the model.Compute that f '(x) = (3 x^2 - 420 x + 4000)/5000 which equals zero at x = 70-10*SQRT(321)/3 and at x = 70+10*SQRT(321)/3, or at around x = 10.28 and x =129.72. As shown in the following graph, the maximum is at x = 10.28. Although f(x)increases to infinity as x gets large, this is beyond the range where our model makes sense.GRAPHING UTILITYy = f(x)-40-202040608010012014020406080100120140160y x Step 5: Answer the question.According to this model, the optimal policy is to sell the pig after 10 days, for a net profit of about $134.(c) The parameter 0.00004 represents the rate at which price is leveling off. Conduct a sensitivity analysis on this parameter. Consider both the optimal time to sell and the resulting profit.Generalize the model from part (b) and lety = f(x) = (0.65 - 0.01 x + a x^2) (200 + 5 x) - 0.45 xwhere currently a = 0.00004. Compute thatf '(x) = (150*a*x^2+x*(4000*a-1)+8)/10 = 0atx = -(SQRT(16000000*a^2-12800*a+1)+4000*a-1)/(300*a).Thendx/de = -(SQRT(16000000*a^2-12800*a+1)+ 6400*a-1)/(300*a^2*SQRT(16000000*a^2-12800*a+1))and so S(x,e) = (dx/de) (e/x) = 0.31. If price is leveling off 10% faster then we thought, then we should wait 3.1% longer to sell the pig . A similar computation yields S(y,e) = 0.008 so that if price is leveling off 1000% faster then we thought, then we should wait 8% longer to sell the pig.(d) Compare the results of part (b) to the optimal solution contained in the text. Comment on the robustness of our assumptions about price.There is not much difference between the results in part (b) and the results in the text. Our model is reasonably robust with respect to the assumption that price is a linear function of time. Given this, the added computational difficulty associated with the quadratic price model is probably not justified.4. An oil spill has fouled 200 miles of Pacific shoreline. The oil company responsible has been given 14 days to clean up the shoreline, after which a fine will be levied in the amount of $10,000/day. The local clean-up crew can scrub 5 miles of beach per week at a cost of $500/day. Additional crews can be brought in at a cost of $18,000 plus$800/day for each crew.(a) How many additional crews should be brought in to minimize the total cost to the company? Use the five-step method. How much will the clean-up cost?Step 1: Ask the question.Variables: c = number of additional crewst = time to clean up spill (days)T= total cost of clean-up ($)F= fine ($)Assumptions:T= 500 t + (18000 + 800 t) c + F200= (5 / 7) (c + 1) tF= 0if t <= 14F= 10,000 (t - 14)if t > 14c is a nonnegative integer, and t >= 0Objective:Minimize T.Step 2: Select the modeling approach.We will model this problem as a one variable optimization problem. See text p. 6.Step 3: Formulate the model.Let x = c and y = T, and writey = f(x) = 500 (280 / (x+1)) +(18,000 + 800 (280 / (x+1))) xif x >= 19 ory = f(x) = 500 (280 / (x+1)) +(18,000 + 800 (280 / (x+1))) x+ 10,000 (280 / (x + 1) - 14)if x < 19. Our goal is to maximize f(x) over the set of nonnegative integers x.Step 4: Solve the model.One way to solve is to minimize over the nonnegative reals, and then specialize to the integers. On 0 <= x < 19 we havef '(x) = 2000*(9*x^2+18*x-1349)/(x+1)^2which is negative on [0, 11.28) and positive on (11.28, 19), so x = 11.28 is the minimum. Then the minimum over the integers occurs at either x = 11 or at x = 12, and we can check that x = 11, f (x) = 508333 is smaller. On x >= 19 we havef '(x) = 6000*(3*x^2+6*x+17)/(x+1)^2which is always positive, and so on this interval the minumum occurs at x = 19, f (x) = 561800. Then the global minimum occurs at x = 11.GRAPHING UTILITYy = f(x)yxStep 5: Answer the question.According to this model, the optimal policy is to bring in 11 additional crews, resulting in a total clean-up cost of around $510,000. Clean-up will take around 23.3 days and the resulting fine will be around $93,000.(b) Examine the sensitivity to the rate at which a crew can clean up the shoreline. Consider both the optimal number of crews and the total cost to the company. Generalize the model in part (a) to obtain the assumption200= r (c + 1) twhere currently r = (5 / 7) miles per day per crew. Then we havey = f(x) = 500 (200 / (r (x+1))) +(18,000 + 800 * 200 / (r (x+1))) xif x >= 19 ory = f(x) = 500 (200 / (r (x+1))) +(18,000 + 800 * 200 / (r (x+1))) x+ 10,000 (200 / (r (x+1)) - 14)if x < 19. For values of r near (5 / 7) the minimum should still occur on the interval (0, 19). Solving0 = f '(x) = 2000*(9*r*x^2+18*r*x+9*r-970)/(r*(x+1)^2)yieldsx = (SQRT(970)-3*SQRT(r))/(3*SQRT(r))and sodx / dr = -SQRT(970)/(6*r^(3/2)).Substituting r = (5 / 7) we obtainS(x, r) = (dx / dr) (r / x) = -0.54so that if the cleanup crews are 10% faster than expected, the optimal number of crews decreases by about 5.4%. If we substitute the formula for the optimal x in terms of r into the formula for y = f(x) in the case x < 19, we obtainy = -2000*(79*r-6*SQRT(970)*SQRT(r)-80)/rand then we can also calculatedy / dr = -2000*SQRT(10)*(3*SQRT(97)*SQRT(r)+8*SQRT(10))/r^2 Substituting r = (5 / 7) we obtainS(y, r) = (dy / dr) (r / y) = -0.88so that if the cleanup crews are 10% faster than expected, the total cost of clean-up decreases by about 8.8%.(c) Examine the sensitivity to the amount of the fine. Consider the number of days the company will take to clean up the spill and the total cost to the company.Generalize the model in part (a) to obtain the assumptionF= a (t - 14)if t > 14where currently a = 10,000 dollars per day. Then for values of a near 10,000 we havey = f(x) = 500 (280 / (x+1)) +(18,000 + 800 (280 / (x+1))) x+ a (280 / (x + 1) - 14)if x < 19. The optimal number of crews is x = SQRT(14)*SQRT(a-300)/30-1 and so the time to finish the clean-up ist = 280 / (x+1) = 600*SQRT(14)/SQRT(a-300)and then we can compute that at a=10,000 we haveS(t,a) = (dt/da)(a/t) = (-300*SQRT(14)/(a-300)^(3/2))*(a/t) = -0.52so that if the fine is raised by 2% then the cleanup time should decrease by about 1%. Substituting the optimal formula for x in terms of a into the equation for y above, we obtainy = 2*(600*SQRT(14)*SQRT(a-300)-7*a+103000)dy/da = 2*SQRT(7)*(300*SQRT(2)-SQRT(7)*SQRT(a-300))/SQRT(a-300)so that at a = 10,000 we haveS(y,a) = (dy/da)(a/y) = 0.17which means that if the fine is increased then the total cleanup cost to the company will go up by about 1.7% for each additional $1,000 per day of fine.(d) The company has filed an appeal on the grounds that the amount of the fine is excessive. Assuming that the only purpose of the fine is to motivate the company to clean up the oil spill in a timely manner, is the fine excessive?Reasonable answers will differ on this question. On the one hand, the fine is only 19% of the total cost, and if the fine were reduced by 50% then the number of days to clean up the spill would increase by about 25% and it would only save the company about 8.5% of the total cost. So the amount of the fine does not seem excessive. On the other hand, if the 14 day limit were extended to 21 days, cleanup would proceed exactly as before, only the company would save $70,000. So in this case the 14 day limit does seem excessive.5. It is estimated that the growth rate of the fin whale population (per year) isr x (1 - x / K), where r = 0.08 is the intrinsic growth rate, K = 400,000 is the maximum sustainable population, and x is the current population, now around 70,000. It is further estimated that the number of whales harvested per year is about .00001 E x, where E is the level of fishing effort in boat-days. Given a fixed level of effort, population will eventually stabilize at the level where growth rate equals harvest rate.(a) What level of effort will maximize the sustained harvest rate? Model as a one-variable optimization problem using the five-step method.Step 1: Ask the question.Variables:x = population (whales)E = level of effort (boat-days)g= growth rate (whales per year)h= harvest rate (whales per year)Assumptions:g= 0.08 x (1 - x / 400,000)h= .00001 E xg= h,x >= 0,E >= 0Objective:Maximize h.Step 2: Select the modeling approach.We will model this problem as a one variable optimization problem. See text p. 6.Step 3: Formulate the model.Let y = h, and writey = f(x) = 0.08 x (1 - x / 400,000).Our goal is to maximize f(x) over the interval x >= 0.Step 4: Solve the model.Compute f '(x) = 0 at x = 200,000, f(x) = 8000 and since the graph of f(x) is a parabola we know this is the global maximum.Step 5: Answer the question.According to this model, the optimal policy is to harvest 8000 whales per year, which requires controlling the level of effort at 4000 boat-days per year. This will maintain the population of whales at 200,000 which is higher than the current population. This indicates that in the past the harvesting rate has exceeded the optimum level according to this model.(b) Examine the sensitivity to the intrinsic growth rate. Consider both the optimum level of effort and the resulting population level.Generalize the model in part (a) to obtain the assumptiong= r x (1 - x / 400,000)where currently r = 0.08. Then we havey = f(x) = r x (1 - x / 400,000)and the optimum is still at x = 200,000 but now f(x) = 100,000 r which leads toE = 50,000 r. ThenS(x , r) = 0S(E , r) = 1because x does not depend on r, and E is proportional to r.(c) Examine the sensitivity to the maximum sustainable population. Consider both the optimum level of effort and the resulting population level.Generalize the model in part (a) to obtain the assumptiong= 0.08 x (1 - x / K)where currently K = 400,000. Then we havey = f(x) = 0.08 x (1 - x / K)and the optimum is at x = K / 2, f(x) = 0.02 K which leads toE = 4000. ThenS(x , K) = 1S(E , K) = 0because E does not depend on K, and x is proportional to K.6. In problem 5, suppose that the cost of whaling is $500 per boat-day, and the price of a fin whale carcass is $6,000.(a) Find the level of effort that will maximize profit over the long term. Model as a one-variable optimization problem using the five-step method.Step 1: Ask the question.Variables:x = population (whales)E = level of effort (boat-days)g= growth rate (whales per year)h= harvest rate (whales per year)R = revenue (dollars per year)C = cost (dollars per year)P = profit (dollars per year)Assumptions:g= 0.08 x (1 - x / 400,000)h= .00001 E xR= 6000 hC= 500 EP = R - Cg= h,x >= 0,E >= 0Objective:Maximize P.Step 2: Select the modeling approach.We will model this problem as a one variable optimization problem. See text p. 6.Step 3: Formulate the model.Setting g = h we see thatE = 0.08 (1 - x / 400,000) / .00001= 8000 - .02 xLet y = P, and writey = f(x) = 6000 (.00001 E x) - 500 E= (.06 x - 500) E= -.0012 x^2 + 490 x - 4,000,000.Our goal is to maximize f(x) over the interval x >= 0.Step 4: Solve the model.Compute f '(x) = 0 at x = 204,167, f(x) = 4.60208*10^7 and since the graph of f(x) is a parabola we know this is the global maximum.Step 5: Answer the question.According to this model, the optimal policy is to harvest 7997 whales per year, which requires controlling the level of effort at 3917 boat-days per year. This will maintain the population of whales at 204,167 and will net the industry an annual profit of around 46 million dollars.(b) Examine the sensitivity to the cost of whaling. Consider both the eventual profit in $ / year and the level of effort.Generalize the model in part (a) to obtain the assumptiony = f(x) = 6000 (.00001 E x) - w E= (.06 x - w) E= -.0012 x^2 + (480+.02 w) x - 8000 w.where currently w = 500. Then the optimum is at x = 200,000 + 25w/3,P = f(x) = (1/12) (w - 24000)^2 which leads to E = (24000 - w)/6. ThenS(P , w) = (dP/dw) (w/P) = -0.04S(E , w) = (dE/dw) (w/E) = -0.02so if the cost of whaling goes up by 10% then the optimal profit decreases by 0.4% and the optimal level of effort decreases by 0.2 %.(c) Examine the sensitivity to the price of a fin whale carcass. Consider both profit and level of effort.Generalize the model in part (a) to obtain the assumptiony = f(x) = c (.00001 E x) - 500 E= (.00001 c x - 500) E= -(c/5,000,000) x^2 + (2c/25 + 10) x - 4,000,000.where currently c = 6000. Then the optimum is at x = 200,000 (c + 125)/c,f(x) = 8000 ( c^2 - 250 c + 15625) / c which leads to E = 4000(c-125)/c. Then S(P , c) = (dy/dc) (c/y) = 1.04S(E , c) = (dE/dc) (c/E) = 0.02so if the price of a fin whale carcass goes up by 10% then the optimal profit increases by about 10.4% and the optimal level of effort increases by 0.2 % .(d) Over the past 30 years there have been several unsuccessful attempts to ban whaling worldwide. Examine the economic incentives for whalers to continue harvesting. In particular, determine the conditions (values of the two parameters: cost per boat-day and price per fin whale carcass) under which harvesting the fin whale produces a sustained profit over the long term.From part (b) we see that the optimal profit is P = f(x) = (1/12) (w - 24000)^2 at $6000per carcass, so that the industry makes a profit whenever the cost of whaling is below $24,000 per boat-day. From part (c) we see that P = 8000 ( c^2 - 250 c + 15625) / c at $500 per boat-day, in which case the industry makes a profit whenever the price per carcass exceeds $125. It is difficult analytically to consider the optimal P as a function of both c and w together, but using our sensitivity results we have approximately thatP = 46,000,000 + 1.04 (46,000/6) (c-6,000) - 0.04 (460,000/5) (w-500)and then P>0 whenever c > 6w/13 or in other words the industry makes a profit as long as the price of a fin whale carcass is a bit more than half of the cost per boat-day of whaling.Thus there is a very strong profit motive to continue whaling.7. Reconsider the pig problem of Example 1.1, but now suppose that our objective is to maximize our profit rate ($/day). Assume that we have already owned the pig for 90 days and have invested $100 in this pig to date.(a) Find the best time to sell the pig. Use the five-step method, and model as a one-variable optimization problem.Step one is the same as in figure 1.1 of the text, except that we add a new variable Q =profit per day ($/day), we assume C = 100 + 0.45 t, Q = P / (t + 90), and our objective is to optimize profit per day. This is a one variable optimization problem. Letting x = t and y = f (x) = Q we are to find the maximum of the functionf (x) = ((200 + 5 x) (0.65 - 0.01 x) - (100+ 0.45 x)) / (x + 90)over the set of all nonnegative x. The graph indicates a maximum around x = 4.5,f (x) = 0.345.GRAPHING UTILITYy = f(x)0.3300.3320.3340.3360.3380.3400.3420.3440.34612345678910y x Computef '(x) = -(x^2+180*x-840)/(20*(x+90)^2) = 0at x = 2*SQRT(2235)-90 or approximately x = 4.55. Then the farmer should sell the pig in 4 or 5 days to maximize profit per day, or the rate at which the farmer earns income.(b) Examine the sensitivity to the growth rate of the pig. Consider both the best time to sell and the resulting profit rate.Let g denote the growth rate of the pig, where currently we assume g = 5 lbs / day. Now we are to find the maximum of the functionf (x) = ((200 +g x) (0.65 - 0.01 x) - (100+ 0.45 x)) / (x + 90)over the set of all nonnegative x. Computef '(x) = -(g*x^2+180*g*x-150*(39*g-167))/(100*(x+90)^2) = 0atx = 5*SQRT(6)*(SQRT(93*g-167)-3*SQRT(6)*SQRT(g))/SQRT(g)and then at g = 5 we haveS(x, g) = (dx / dg) (g / x) = 4.82so that if the pig grows 1% faster than expected, we should wait 5% longer to sell the pig. Substituting into y = f(x) we can also compute thatS(y, g) = (dy / dg) (g / y) = 0.42so that if the pig grows 10% faster then expected we should gain an additional 4% profit per day.(c) Examine the sensitivity to the rate at which the price for pigs is dropping. Consider both the best time to sell and the resulting profit rate.Let r denote the rate at which price is falling, where currently r = 0.01 ($/day). Then we are to maximizef (x) = ((200 + 5 x) (0.65 - r x) - (100+ 0.45 x)) / (x + 90)over the set of all nonnegative x. Computef '(x) = -(5*r*x^2+900*r*x+6*(3000*r-37))/(x+90)^2 = 0atx = SQRT(30)*(SQRT(3750*r+37)-15*SQRT(30)*SQRT(r))/(5*SQRT(r))and then at r = 0.01 we haveS(x, r) = (dx / dr) (r / x) = -5.16so that if the price drops 1% faster than expected, we should sell the pig 5% sooner. Substituting into y = f(x) we can also compute thatS(y, r) = (dy / dr) (r / y) = -0.31so that if the price drops 10% faster then expected then we will lose about 3% of our expected profit per day.8. Reconsider the pig problem of Example 1.1, but now take into account the fact that the growth rate of the pig decreases as the pig gets older. Assume that the pig will be fully grown in another five months.(a) Find the best time to sell the pig in order to maximize profit. Use the five-step method, and model as a one-variable optimization problem.The results of step one are the same as in figure 1.1 of the text, except that now we assume the growth rate of the pig is r (lbs/day) where r = 5 - t / 30 so that the weightw (lbs) of the pig after t days is w = 200 + (5 - t / 30) t. Then we need to maximizef (x) = (200 + (5 - x / 30) x) (0.65 - 0.01 x) - 0.45 xover the set of all nonnegative x. The graph indicates a maximum around x = 6,f (x) = 132.GRAPHING UTILITYy = f (x)132.5132.0131.5y131.0130.5130.0xWe compute thatf '(x) = (3*x^2-430*x+2400)/3000 = 0at x = 215/3-5*SQRT(1561)/3 = 5.82 so that f (x) = 132.29. Then the farmer should sell the pig after 6 days, and the expected net profit will be about $132.(b) Examine the sensitivity to the time it will take until the pig is fully grown. Consider both the best time to sell and the resulting profit.We generalize our previous model. Let a denote the rate at which the growth of the pig slows. Currently a = 1.0 lbs/day per month. Now the problem is to maximizef (x) = (200 + (5 - a x / 30) x) (0.65 - 0.01 x) - 0.45 xover the set of all nonnegative x. For values of a near 1.0 the maximum should occur at a point near x = 6 where f '(x) = 0. We compute thatf '(x) = (3*a*x^2-10*x*(13*a+30)+2400)/3000 = 0at x = -5*(SQRT(169*a^2+492*a+900)-13*a-30)/(3*a). Then at a = 1.0 we haveS(x, a) = (dx / da) (a / x) = -0.28so that if the pig stops growing 10% sooner than expected, then we should sell the pig 3% sooner. Substituting into the formula for y = f (x) we may also compute thatS(y, a) = (dy / da) (a / y) = -0.005so that the resulting profit is almost totally insensitive to the rate at which the pig stops growing. This makes sense because the growth rate of the pig will not change much in the 6 or so days until we sell.9. A local daily newspaper with a circulation of 80,000 subscribers is thinking of raising its subscription price. Currently the price is $1.50 per week, and it is estimated that the paper would lose 5,000 subscribers if the rate were to be raised by 10 cents/week.(a) Find the subscription price that maximizes profit. Use the five-step method, and model as a one-variable optimization problem.Step 1: Ask the question.Variables:p = subscription price ($/paper)s = number of subscriptions (papers)P= profit ($)Assumptions:s= 80000 - 50000 (p - 1.50)P= p ss>= 0p >= 0Objective:Maximize P.Step 2: Select the modeling approach.We will model this problem as a one variable optimization problem. See text p. 6.Step 3: Formulate the model.Let x = p and y = P, and writey = f(x) = x (80000 - 50000 (x - 1.50)).Our goal is to maximize f(x) over the interval [0, 3.10] since these are the only values of x that satisfy both s >= 0 and p >= 0. In other words, price cannot be negative, and according to our model the number of subscriptions drops to zero when price is raised to $3.10.Step 4: Solve the model.A graph of the function f (x) shows that the maximum occurs at around x = 1.5 andf (x) = 120,000.GRAPHING UTILITYy = f (x)-200000200004000060000800001000001200001400000.00.5 1.0 1.52.0 2.53.0 3.5y xCompute f '(x) = 5000*(31-20*x) = 0 at x = 31/20 = 1.55, f(x) = 120125 which is the global maximum.Step 5: Answer the question.According to this model, the optimal policy is to raise the price of the paper by 5 cents to $1.55 per week. The resulting profit (actually it is revenue since we have not accounted for any costs in our model) is $120,125 per week as opposed to $120,000 currently.(b) Examine the sensitivity of your answer in part (a) to the assumption of 5,000 lost subscribers. Calculate the optimal subscription rate assuming that this parameter is 3,000, 4,000, 5,000, 6,000, or 7,000.We repeat the above procedure with the parameter 10 n = 50000 replaced by 30000, ...to obtain the following results:n x y3000 2.081302104000 1.751224905000 1.551201256000 1.421204107000 1.32122220(c) Let n = 5,000 denote the number of subscribers lost when the subscription price increases by 10 cents. Calculate the optimal subscription price p as a function of n, and use this formula to determine the sensitivity S(p,n).Now we need to maximizef (x) = x (80000 - 10 n (x - 1.50))where currently n = 5000. For values of n near 5000 the maximum should occur at the point near x = 1.50 where f '(x) = 0. We calculate thatf '(x) = -5*(4*n*x-3*n-16000) = 0at p = x = (3*n+16000)/(4*n). Then at n = 5000 we find thatS(p, n) = (dp / dn) ( n / p) = -16000/(3*n+16000) = -16/31 = -0.52so that if the number n of lost subscriptions for a 10 cent price increase is 20% higher than expected, then the optimal price is about 10% lower. This is in rough agreement with the results of part (b) above.(d) Should the paper change its subscription price? Justify your conclusions in plain English.The newspaper should not make a change in its subscription price based on the results of this model. The chart in part (b) shows that for current estimate of n = 5000 we are already very close to the optimal subscription price. In fact the results of part (a) show that we are within 5 cents. If we did raise the price by 5 cents we would only increase our revenue by an estimated $125 or about 0.10 percent. The likely magnitude of error in our estimate of n is probably at least 10 or 20 percent, and so in fact the optimal price may be slightly higher or lower than the current price of $1.50 per week.。
华东师大数模第2章答案02~ch2_solutions
> > > > >
dxdK1:=diff(x,K1): dydK1:=diff(y,K1): assign(K1=150000); sxK1:=dxdK1*(K1/x); syK1:=dydK1*(K1/y); sxK1 := 1.001502253 syK1 := -.01760602687
Then S(x, K_1) = +1.0015 and S(y, K_1) = -0.0176 so that if the carrying capacity for Blue whales increases by 10% then the optimal population for Blue whales increases by about 10% and the optimal population for Fin whales stays about the same. Now compute that > restart: > z:=0.05*x*(1 - x / 150000) - 10^(-8)* x* y + 0.08* y* (1 - y / K2) - 10^(-8)* x*y; 1 1 y z := .05 x x x y + .08 y 1 − − 1 − 150000 50000000 K2 > dzdx:=diff(z,x); > dzdy:=diff(z,y); dzdx := .05 − .6666666666 10-6 x − dzdy := − 1 x + .08 − 1 50000000 .16 y K2 y
{ y = 196544.8172, x = 69103.65549 }
《数学建模》期末考试试卷一与参考答案
《数学建模》期末考试试卷 班级 姓名 学号一、(15分)以色列的某社区联盟,其农业生产受农田面积和灌溉配水量的限制,其资料如表1所示,适合该地区种植的农作物有甜菜、棉花和栗子,其每英亩的期望净收益、用水量及可种植的最大面积如表2所示。
表1 农田面积和灌溉配水量 表2 农作物期望净收益、用水量试问,该社区联盟应如何安排这三种农作物的生产,方使总的收益最大?建立线性规划问题的数学模型并写出用LINGO 求解的程序。
二、(15分)用单纯形方法求解线性规划问题。
⎪⎩⎪⎨⎧≥≥≥≤++≤++++=000242126042..61314S max 321321321321x x x x x x x x x t s x x x ;;三、(15分)上海红星建筑构配件厂是红星集团属下之制造建材设备的专业厂家。
其主要产品有4种,分别用代号A 、B 、C 、D 表示,生产A 、B 、C 、D 四种产品主要经过冲压、成形、装配和喷漆四个阶段。
根据工艺要求及成本核算,单位产品所需要的加工时间、利润以及可供使用的总工时如下表所示:在现有资源的条件下如何安排生产,可获得利润最大?现设置上述问题的决策变量如下:1234,,,x x x x 分别表示A 、B 、C 、D 型产品的日产量,则可建立线性规划模型如下:⎪⎪⎪⎩⎪⎪⎪⎨⎧≥≤+++≤+++≤+++≤++++++=0,,,300048462000552424005284480..81169max 432143214321432143214321x x x x x x x x x x x x x x x x x x x x t s x x x x z 利用LINGO10.0软件进行求解,得求解结果如下:Global optimal solution found at iteration: 4Objective value: 4450.000 Variable Value Reduced Cost X1 400.0000 0.000000 X2 0.000000 0.5000000 X3 70.00000 0.000000 X4 10.00000 0.000000 Row Slack or Surplus Dual Price 1 4450.000 1.000000 2 0.000000 2.500000 3 610.0000 0.000000 4 0.000000 0.5000000 5 0.000000 0.7500000(1)指出问题的最优解并给出原应用问题的答案;(2)写出线性规划问题的对偶线性规划问题,并指出对偶问题的最优解;(3)灵敏度分析结果如下:Ranges in which the basis is unchanged: Objective Coefficient RangesCurrent Allowable AllowableVariable Coefficient Increase Decrease X1 9.000000 0.5000000 0.1666667 X2 6.000000 0.5000000 INFINITY X3 11.00000 0.3333333 1.000000 X4 8.000000 1.000000 1.000000 Righthand Side RangesRow Current Allowable AllowableRHS Increase Decrease2 480.0000 20.00000 80.000003 2400.000 INFINITY 610.00004 2000.000 400.0000 20.000005 3000.000 40.00000 280.0000对灵敏度分析结果进行分析 四、(15分)(1)叙述层次分析法的步骤。
华中师范大学数学模型期末考试试卷
专业:
院赛的结果,比如 3 通过箭头指向 2 表明 3 战胜了 2,请用数学建 模的方法给出四位选手的比赛排名,只需要写出思路或大致过程。
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得分 评阅人
二、计算题:(共 2 题,每题 13 分)
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(1)若 55 元可买到 1 桶牛奶,应否作这项投资?若投资,每天最多购买多少桶牛奶?为什么?
(2)如果可以聘用临时工人以增加劳动时间,付给工人的工资最多是每小时几元?为什么?
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得分 评阅人
三、算法题:(共 3 题,每题 15 分)
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1、某航空公司每天有三个航班服务于 A,B,C,H 四个城市,其中 H 可以供转机使用,三个航班 的出发地-目的地分别为 AH,HB,HC,可搭乘旅客的最大数量分别为 120 人,100 人,110 人, 机票的价格分头等舱和经济舱两类,经市场调查,公司销售部得到了每天旅客的相关信息,见
华中师范大学 20 12–2013 学年第二学期 期末考试试卷(A 卷)
《数学模型》试题及参考答案
A卷2009-2010学年第2学期《数学建模》试卷专业班级姓名分组号与学号开课系室数学与计算科学学院考试日期 2010 年7月题号一二三四五六七八总分得分阅卷人数学建模试卷(1007A)一(10)(1)简述数学模型的概念,分析数学模型与数学建模的关系。
(2)建立数学模型的一般方法是什么?在建模中如何应用这些方法,结合实例加以说明。
二(10分)、(1).简述数学建模的一般步骤,分析每个步骤的主要内容和注意事项。
(2)简述数学模型的表现形态,并举例说明。
第一页三(10分)、(1)简述合理分配席位的Q-值方法,包括方法的具体实施过程,简述分配席位的理想化原则。
(2)建立录像机记数器读数与录像带转过时间之间的关系模型,包括模型假设与模型建立全过程。
四(15分)(1)建立不允许缺货情况下的存储模型,确定订货周期和订货量(包括问题叙述,模型假设和求解过程).(2)建立不允许缺货的生产销售存贮模型.设生产速率为常数k,销售速率为常数r,k r.在每个生产周期T内,开始的一段时间(0 t T0)一边生产一边销售,后来的一段时间(T0t T)只销售不生产.设每次生产开工费为c1,单位时间每件产品贮存费为c2,(a)求出存储量q(t) 的表示式并画出示意图。
(2)以总费用最小为准则确定最优周期T,讨论kr的情况.第二页五(15分)、(1)建立传染病传播的SIS模型并求解(简述假设条件和求解过程),(2)建立SIR模型,并用相平面方法求解,在相平面上画出相轨线并进行分析。
六(15分)(1)建立一般的战争模型,分析各项所表示的含义。
(2)在假设x0y0,b 9a条件下对正规战争模型(忽略增援和非战斗减员)进行建模求解,确定战争结局和结束时间。
第三页七(15分)设渔场鱼量的自然增长服从模型x rxln N,又单位时间捕捞量为xh Ex.讨论渔场鱼量的平衡点及其稳定性,求最大持续产量hm及获得最大产量的捕捞强度E m 和渔场鱼量水平x0.八(10分)假设商品价格y k和供应量x k满足差分方程y k1 y0(xk1x k x0), 02xk1 x0(y k y0) 0求差分方程的平衡点,推导稳定条件第四页A卷2009-2010学年第2学期《数学模型》试题参考答案与评分标准专业班级开课系室数学与计算科学学院考试日期2010年7月数学建模试卷(1007A)参考答案与评分标准一(10)(1)简述数学模型的概念,分析数学模型与数学建模的关系。
福师《数学建模》在线作业一1答案
福师《数学建模》在线作业一-0005试卷总分:100 得分:0一、判断题(共40 道试题,共80 分)1.数据的动态性又称为记忆性A.错误B.正确正确答案:B2.大学生走向工作岗位后就不需要数学建模了A.错误B.正确正确答案:A3.图示法是一种简单易行的方法A.错误B.正确正确答案:B4.明显歪曲实验结果的误差为过失误差A.错误B.正确正确答案:B5.任意齐次线性方程组的基本解组仅有一组A.错误B.正确正确答案:A6.任何一个模型都会附加舍入误差A.错误B.正确正确答案:B7.模型不具有转移性A.错误B.正确正确答案:A8.获取外部信息时必须考虑其可靠性和权威性A.错误B.正确正确答案:B9.求常微分方程的基本思想是将方程离散化转化为递推公式以求出函数值A.错误B.正确正确答案:B10.利用乘同余法可以产生随机数A.错误B.正确正确答案:B11.数学建模的真实世界的背景是可以忽视的A.错误B.正确正确答案:A12.预测战争模型是牛顿提出的A.错误B.正确正确答案:A13.引言是整篇论文的引论部分A.错误B.正确正确答案:B14.数学建模是一种抽象的模拟,它用数学符号等刻画客观事物的本质属性A.错误B.正确正确答案:B15.建模中的数据需求常常是一些汇总数据A.错误B.正确正确答案:B16.对变量关系拟合时精度越高越好A.错误B.正确正确答案:A17.面向事件法又称时间增量法A.错误B.正确正确答案:A18.原型指人们在社会和生产实践中关心和研究的现实世界中的实际对象A.错误B.正确正确答案:B19.题面见图片A.错误B.正确正确答案:B20.现在世界的科技文献不到2年就增加1倍A.错误B.正确正确答案:A21.在构造一个系统的模拟模型时要抓住系统中的主要因素A.错误B.正确正确答案:B22.没有创新,人类就不会进步A.错误B.正确正确答案:B23.渡口模型涉及到先到后服务的排队问题A.错误B.正确正确答案:A24.建模主题任务是整个工作的核心部分A.错误B.正确正确答案:B25.小组讨论要回避责任A.错误B.正确正确答案:A26.有的建模问题可利用计算机求解A.错误B.正确正确答案:B27.利用理论分布基于对问题的实际假设选择适当的理论分布可以对随机变量进行模拟A.错误B.正确正确答案:B28.参考文献要反映出真实的科学依据A.错误B.正确正确答案:B29.量纲分析是20世纪提出的在物理领域建立数学模型的一种方法A.错误B.正确正确答案:B30.利用偏回归平方和评价一个自变量在一组自变量中的重要性A.错误B.正确正确答案:B31.现在公认的科学单位制是SI制A.错误B.正确正确答案:B32.随机误差不是由偶然因素引起的A.错误B.正确正确答案:A33.数学建模仅仅设计变量A.错误B.正确正确答案:A34.研究新产品销售模型是为了使厂家和商家对新产品的推销速度做到心中有数A.错误B.正确正确答案:B35.我国对异常值没有颁布标准A.错误B.正确正确答案:A36.数学建模没有唯一正确答案A.错误B.正确正确答案:B37.利润受销售量的影响和控制A.错误B.正确正确答案:B38.最小二乘法估计是常见的回归模型参数估计方法A.错误B.正确正确答案:B39.模型的成功与否取决于经受住实践检验A.错误B.正确正确答案:B40.关键词不属于主题词A.错误B.正确正确答案:A二、多选题(共10 道试题,共20 分)1.建立数学模型时可作几方面的假设____A.关于是否包含某些因素的假设B.关于条件相对强弱及各因素影响相对大小的假设C.关于变量间关系的假设D.关于模型适用范围的假设正确答案:ABCD2.估计模型中参数值的常用方法有____A.直接查阅资料B.图解法C.统计法D.机理分析法正确答案:ABCD3.使用模拟系统应达到的目标有()A.描述一个现有的系统B.探索一个假设的系统C.设计一个改进的系统正确答案:ABC4.实验误差有____A.随机误差B.系统误差C.过失误差正确答案:ABC5.建立微分方程模型一般的步骤是____A.把用语言叙述的情况化为文字方程B.给出问题所涉及的原理或物理定律C.列出微分方程,列出该微分方程的初始条件或其他条件D.求解微分方程,确定微分方程中的参数,最后求出问题的答案正确答案:ABCD6.用模拟模型去解决实际问题时的注意事项有____A.应该做足够多次的模拟运行后,对结果进行分析B.注意抓住系统中的主要因素C.把握原则D.牢记建模目标E.模拟模型的每一次模拟都是从特定的初始状态开始F.一个系统是在稳定状态条件下按正常情况设计的正确答案:ABCDEF7.采取面向事件法进行系统模拟的步骤是____A.写出实体(实体的特征),状态,活动B.确定系统的运转规则,画出说明事件和活动的流向图C.绘制“轨迹表”表格,产生随机数进行模拟D.写轨迹表正确答案:ABCD8.观察实际问题中的平衡现象的方法有______A.从长期的宏观的角度着眼,在大局上或整体上进行研究B.从瞬时的局部的角度着眼,把微小结构及瞬时变化作为问题来研究C.利用宏观模型去观察D.利用微观模型去观察正确答案:ABCD9.数学模型的误差原因有____A.来自建模假设的误差B.来自近似求解方法的误差C.来自计算工具的舍入误差D.来自数据测量的误差正确答案:ABCD10.产生随机数的数学方法有____A.乘同余法B.混合同余法C.除同余法D.独立同余法正确答案:AB。
数学建模试题卷及答案
西安邮电大学2011-2012第一学期《数学建模》选修课试题卷班级:软件1003班姓名:学号:成绩:一、解释下列词语,并举例说明(每小题满分5分,共15分)1.模型答:模型:所研究的系统、过程、事物或概念的一种表达形式,也可指根据实验、图样放大或缩小而制作的样品,一般用于展览或实验或铸造机器零件等用的模子。
例如飞机模型,用压制或浇灌方法使材料成为一定形状的工具。
通称“模型”。
2.数学模型答:数学模型:用数学语言描述的一类模型。
数学模型可以是一个或一组代数方程、微分方程、差分方程、积分方程或统计学方程,也可以是它们的某种适当的组合,通过这些方程定量地或定性地描述系统各变量之间的相互关系或因果关系。
除了用方程描述的数学模型外,还有用其他数学工具,如代数、几何、拓扑、数理逻辑等描述的模型。
需要指出的是,数学模型描述的是系统的行为和特征而不是系统的实际结构。
3.抽象模型答:抽象模型:是三维建模里这么称呼的就跟抽象雕塑的一样的。
实际不存在,理论上却存在,并用思维对事物进行客观认识的理论或者框架。
对获得的感性材料和感性经验,运用理性思维进行一番老粗取梢、去伪存真、由此及彼、由表及里的改造制作工夫,去掉事物非本质的、表面的、偶然的东西,抽取出事物本质的、内在的、必然的东西,揭示客观对象的本质和规律而建立的模型。
二、简答题(每小题满分8分,共24分)1.模型的分类答:按照模型替代原型的方式,模型可以简单分为形象模型和抽象模型两类,形象模型:直观模型、物理模型、分子结构模型等;抽象模型:思维模型、符号模型,数学模型等。
2.数学建模的基本步骤答:(1)建模准备:数学建模是一项创新活动,它所面临的课题是人们在生产和科研中为了使认识和实践进一步发展必须解决的问题。
建模准备就是要了解问题的实际背景,明确建模的目的,掌握对象的各种信息,弄清实际对象的特征,情况明才能方法对;(2)建模假设:根据实际对象的的特征和建模的目的,在掌握必要资料的基础上,对原型进行抽象、简化,把那些反映问题本质属性的形态、量及其关系抽象出来,简化掉那些非本质的因素,使之摆脱原型的具体复杂形态,形成对建模有用的信息资源和前提条件,并且用精确的语言作出假设,是建模过程关键的一步。
数学建模题目及答案-数学建模100题
09级数模试题1. 把四只脚的连线呈长方形的椅子往不平的地面上一放,通常只有三只脚着地,次,就可以使四只脚同时着地, 放稳了。
试作合理的假设并建立数学模型说明这个现象。
(15 分)解:对于此题,如果不用任何假设很难证明,结果很可能是否定的。
因此对这个问题我们假设 : (1 )地面为连续曲面(2) 长方形桌的四条腿长度相同(3) 相对于地面的弯曲程度而言,方桌的腿是足够长的 (4) 方桌的腿只要有一点接触地面就算着地。
那么,总可以让桌子的三条腿是同时接触到地面。
坐标系如图所示,方桌的四条腿分别在A 、B 、C 、D 处,A 、的初始位置在与x 轴平行,再假设有一条在x 轴上的线ab,则ab 也 与A 、B ,C 、D 平行。
当方桌绕中心 0旋转时,对角线ab 与x 轴的 夹角记为V容易看岀,当四条腿尚未全部着地时,腿到地面的距离是不确 定的。
为消除这一不确定性,令f(v)为A B 离地距离之和,g(r)为CD 离地距离之和,它们的值由h 唯一确定。
由假设(1 ),f(R ,gU) 均为二的连续函数。
又由假设(3),三条腿总能同时着地,不妨设f(0) =0, g(0) 0g (若g(0)也为o ,则初始时刻已四条腿着地,不必再旋转) ,于是问题归结为:已知f(v),g(v)均为V 的连续函数,f(0)=0, g(0)0且对任意 二有 f®)g(r °) = o , 求证存在某一二0,使 f 仇)g&0)=0。
证明:当9 =n 时,AB 与CD 互换位置,故f (二)• 0,g (二)=0。
作h(3 = f()划),显然,h(^ )也是二的连续函数,h(0) = f (0) - g(0) ::: 0而h(「:)= f (二)-g (二)• 0,由连续函数的取零值定 理,存在^0,0「0 :::二,使得h 仇)=0,即fU 。
)= gp 0)。
又由于f (入沟厲)=0,故必有 f 厲)=gC 。
华师数学建模考试资料
数学建模名词解释:一阶差分方程标准答案:2.第9题名词解释:数学模型标准答案:数学模型(Mathematical Model)就是由数字、字母或者其她数学符号组成得,描述现实对象数量规律得数学公式、图形或算法、3.第10题名词解释:二阶差分方程4。
第15题名词解释:(1)线性规划模型;(2)线性规划模型得可行域;(3)线性规划模型得最优解与最优值;(4)不可行得线性规划模型;(5)无界得线性规划模型、标准答案:5。
第4题标准答案:6。
第11题司机在驾驶过程中遇到突发事件会紧急刹车,从司机决定刹车到车完全停住汽车行驶得距离称为刹车距离,车速越快,刹车距离越长、请问刹车距离与车速之间具有怎样得数量关系7.第12题考虑弹簧-质量系统,收集弹簧伸长得长度与弹簧末端悬挂得质量得实验数据,记录在表1(单位省略)、请计算出伸长与质量得函数关系得经验公式、表1 弹簧伸长与质量得测量数据质量50100150200250300伸长1、0001、8752、7503、2504、3754、875质量350400450500550伸长5、6756、5007、2508、0008、750标准答案:8.第14题(接续47 酶促反应(1)与48酶促反应(2))请分析Michaelis—Menten模型非线性拟合与线性化拟合得结果有何区别?原因就是什么?标准答案:您得答案:题目分数:4、0此题得分:0、09.第1题阅读材料电声器材厂在生产扬声器得过程中,有一道重要得工序:使用AB胶粘合扬声器中得磁钢与夹板、长期以来,由于对AB胶得用量没有一个确定得标准,经常出现用胶过多,胶水外溢;或用胶过少,产生脱胶,影响了产品质量、表1就是一些恰当用胶量得具体数据、2设自变量x为磁钢面积,因变量y为恰当用胶量,用以下MATLAB脚本做一元线性回归分析得计算:x=[11、0;19、4;26、2;46、6;56、6;67、2;125、2;189、0;247、1;443、4];y=[0、164;0、396;0、404;0、664;0、812;0、972;1、688;2、86;4、076;7、332];X=[ones(size(x)),x];[b,bint,r,rint,stat]=regress(y,X)命令窗口显示得计算结果:b =-0、101210、016546bint =-0、24763 0、0452090、015728 0、017365r =0、08320、176210、071696—0、0058489-0、023312-0、038703-0、28239-0、166040、0886160、096575rint =-0、2348 0、4012-0、11393 0、46635—0、2522 0、39559-0、33976 0、32806-0、35828 0、31166-0、374080、29667-0、51782 -0、046954—0、468950、13686—0、2249 0、40213-0、077904 0、27105stat =0、99633 2174 4、948e-011 0、02121问题请将计算结果整理成表格,并进行分析、标准答案:10。
《数学建模》课后习题及答案
第一部分课后习题1.学校共1000名学生,235人住在A宿舍,333人住在B宿舍,432人住在C宿舍。
学生们要组织一个10人的委员会,试用下列办法分配各宿舍的委员数:(1)按比例分配取整数的名额后,剩下的名额按惯例分给小数部分较大者。
(2)2.1节中的Q值方法。
(3)d’Hondt方法:将A,B,C各宿舍的人数用正整数n=1,2,3,…相除,其商数如下表:将所得商数从大到小取前10个(10为席位数),在数字下标以横线,表中A,B,C行有横线的数分别为2,3,5,这就是3个宿舍分配的席位。
你能解释这种方法的道理吗。
如果委员会从10人增至15人,用以上3种方法再分配名额。
将3种方法两次分配的结果列表比较。
(4)你能提出其他的方法吗。
用你的方法分配上面的名额。
2.在超市购物时你注意到大包装商品比小包装商品便宜这种现象了吗。
比如洁银牙膏50g装的每支1.50元,120g装的3.00元,二者单位重量的价格比是1.2:1。
试用比例方法构造模型解释这个现象。
(1)分析商品价格C与商品重量w的关系。
价格由生产成本、包装成本和其他成本等决定,这些成本中有的与重量w成正比,有的与表面积成正比,还有与w无关的因素。
(2)给出单位重量价格c与w的关系,画出它的简图,说明w越大c越小,但是随着w 的增加c减少的程度变小。
解释实际意义是什么。
3.一垂钓俱乐部鼓励垂钓者将调上的鱼放生,打算按照放生的鱼的重量给予奖励,俱乐部只准备了一把软尺用于测量,请你设计按照测量的长度估计鱼的重量的方法。
假定鱼池中只有一种鲈鱼,并且得到8条鱼的如下数据(胸围指鱼身的最大周长):先用机理分析建立模型,再用数据确定参数4.用宽w的布条缠绕直径d的圆形管道,要求布条不重叠,问布条与管道轴线的夹角 应多大(如图)。
若知道管道长度,需用多长布条(可考虑两端的影响)。
如果管道是其他形状呢。
5.用已知尺寸的矩形板材加工半径一定的圆盘,给出几种简便、有效的排列方法,使加工出尽可能多的圆盘。
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某成功人士向学院捐献20万元设立优秀本科生奖学金,学院领导打算将这笔捐款以整存整取一年定期的形式存入银行,第二年一到期就支取,取出一部分作为当年的奖学金,剩下的继续以整存整取一年定期的形式存入银行……请你研究这个问题,并向学院领导写一份报告.解:记存款的年利息为r ,由于一开始存入银行的本金为x0,第k 年存入银行的钱为X k,并且每年取出当奖金的钱为b,则它们之间存在的关系有:每年利息=本年存入款项⨯ 年利息每年取出款项=上一年存入款项+每年利息每年存入款项=每年取出款项- 奖金列式得:由上式解得由实际情况,已知x0=20(万元),r在近10多年的变化幅度在2%~4%之间,我们取3个值,分别为2%,3%,4%,(1)当年利率为2%时,每年存入款项随奖金数变化如下年数\奖金数额 2千元 4千元 6千元0 20.0000 20.0000 20.00001.0000 20.2000 20.0000 19.80002.0000 20.4040 20.0000 19.59603.0000 20.6121 20.0000 19.38794.0000 20.8243 20.0000 19.17575.0000 21.0408 20.0000 18.95926.0000 21.2616 20.0000 18.73847.0000 21.4869 20.0000 18.51318.0000 21.7166 20.0000 18.28349.0000 21.9509 20.0000 18.049110.0000 22.1899 20.0000 17.810111.0000 22.4337 20.0000 17.566312.0000 22.6824 20.0000 17.317613.0000 22.9361 20.0000 17.063914.0000 23.1948 20.0000 16.805215.0000 23.4587 20.0000 16.541316.0000 23.7279 20.0000 16.272117.0000 24.0024 20.0000 15.997618.0000 24.2825 20.0000 15.717519.0000 24.5681 20.0000 15.431920.0000 24.8595 20.0000 15.140521.0000 25.1567 20.0000 14.843322.0000 25.4598 20.0000 14.540223.0000 25.7690 20.0000 14.231024.0000 26.0844 20.0000 13.915625.0000 26.4061 20.0000 13.593926.0000 26.7342 20.0000 13.265827.0000 27.0689 20.0000 12.931128.0000 27.4102 20.0000 12.589829.0000 27.7584 20.0000 12.2416 30.0000 28.1136 20.0000 11.8864①当年利率为2%,学金定为4千元时,因为0,100><<x r , 经验算得知rb x x k ==0,因此存款的数额将趋于稳定.②当年利率为2%,奖学金的数额大于4 千元时,k x 单调递减并且将在某一年变为零.同理,当奖学金的数额小于4 千元时,存款的数额将会无限增长. (2) 当年利率为3%时,每年存入款项随奖金数变化如下年数\奖金数额4千元6千元8千元0 20.0000 20.0000 20.00001.0000 20.2000 20.0000 19.80002.0000 20.4060 20.0000 19.59403.0000 20.6182 20.0000 19.38184.0000 20.8367 20.0000 19.16335.0000 21.0618 20.0000 18.93826.0000 21.2937 20.0000 18.70637.0000 21.5325 20.0000 18.46758.0000 21.7785 20.0000 18.22159.0000 22.0318 20.0000 17.968210.0000 22.2928 20.0000 17.707211.0000 22.5616 20.0000 17.438412.0000 22.8384 20.0000 17.161613.0000 23.1236 20.0000 16.876414.0000 23.4173 20.0000 16.582715.0000 23.7198 20.0000 16.280216.0000 24.0314 20.0000 15.968617.0000 24.3523 20.0000 15.647718.0000 24.6829 20.0000 15.317119.0000 25.0234 20.0000 14.976620.0000 25.3741 20.0000 14.625921.0000 25.7353 20.0000 14.264722.0000 26.1074 20.0000 13.892623.0000 26.4906 20.0000 13.509424.0000 26.8853 20.0000 13.114725.0000 27.2919 20.0000 12.708126.0000 27.7106 20.0000 12.289427.0000 28.1419 20.0000 11.858128.0000 28.5862 20.0000 11.413829.0000 29.0438 20.0000 10.956230.0000 29.5151 20.0000 10.4849①年利率为3%,学金定为6千元时,因为0,100><<x r , 经验算得知r b x x k ==0,因此存款的数额将趋于稳定. ② 当年利率为3%,奖学金的数额大于6 千元时,k x 单调递减并且将在某一年变为零.同理,当奖学金的数额小于6 千元时,存款的数额将会无限增长.(3) 当年利率为4%时,每年存入款项随奖金数变化如下 年数\奖金数额 6千元 8千元 1万元0 20.0000 20.0000 20.00001.0000 20.2000 20.0000 19.80002.0000 20.4080 20.0000 19.59203.0000 20.6243 20.0000 19.37574.0000 20.8493 20.0000 19.15075.0000 21.0833 20.0000 18.91676.0000 21.3266 20.0000 18.67347.0000 21.5797 20.0000 18.42038.0000 21.8428 20.0000 18.15729.0000 22.1166 20.0000 17.883410.0000 22.4012 20.0000 17.598811.0000 22.6973 20.0000 17.302712.0000 23.0052 20.0000 16.994813.0000 23.3254 20.0000 16.674614.0000 23.6584 20.0000 16.341615.0000 24.0047 20.0000 15.995316.0000 24.3649 20.0000 15.635117.0000 24.7395 20.0000 15.260518.0000 25.1291 20.0000 14.870919.0000 25.5342 20.0000 14.465820.0000 25.9556 20.0000 14.044421.0000 26.3938 20.0000 13.606222.0000 26.8496 20.0000 13.150423.0000 27.3236 20.0000 12.676424.0000 27.8165 20.0000 12.183525.0000 28.3292 20.0000 11.670826.0000 28.8623 20.0000 11.137727.0000 29.4168 20.0000 10.583228.0000 29.9935 20.0000 10.006529.0000 30.5933 20.0000 9.406730.0000 31.2170 20.0000 8.7830①年利率为4%,学金定为8千元时,因为0,100><<x r , 经验算得知r b x x k ==0,因此存款的数额将趋于稳定. ② 当年利率为4%,奖学金的数额大于8 千元时,k x 单调递减并且将在某一年变为零.同理,当奖学金的数额小于8 千元时,存款的数额将会无限增长.某种山猫在较好、中等及较差的自然环境下,年平均增长率分别为1.68%、0.55%和-4.5%. 假设开始时有100只山猫,按以下情况分别讨论山猫数量逐年变化的过程及趋势:(1) 三种自然环境下25年的变化过程,结果要列表并图示;(2) 如果每年捕获3只,山猫数量将如何变化?会灭绝吗?如果每年只捕获1只呢?(3) 在较差的自然环境下,如果要使山猫数量稳定在60只左右,每年要人工繁殖多少只?①解记第k年山猫x k,设自然坏境下的年平均增长率为r,则列式得x k+1=(1+r)x k, k=0,1,2…其解为等比数列x k=x0(1+r)k, k=0,1,2…当分别取r=0.0168 , 0.0055和-0.0450时,山猫的数量在25年内不同的环境下的数量演变为年较好中等较差0 100 100 1001 102 101 962 103 101 913 105 102 874 107 102 835 109 103 796 111 103 767 112 104 728 114 104 699 116 105 6610 118 106 6311 120 106 6012 122 107 5813 124 107 5514 126 108 5215 128 109 5016 131 109 4817 133 110 4618 135 110 4419 137 111 4220 140 112 4021 142 112 3822 144 113 3623 147 113 3524 149 114 3325 152 115 32从上可以得出结论:(1)在较好的自然环境下即r=0.0168时,x k单调增趋于无穷大,山猫的数量将无限增长;(2)在中等的自然环境下即r=0.0055时,x k单调增并且趋于稳定值;(3)在较差的环境中即r=-0.0450时,x k单调衰减趋于0,山猫将濒临灭绝。