华中农业大学2009研究生入学考试数学试题
2009-2019真题试卷演练(数学一)试题答案及分析
y cos xdxdy 0, I3 2
y cos xdxdy 0 ,
{( x, y )| y x,0 x1}
{( x, y )| y x,0 x1}
所以正确答案为 A.
(3)设函数 y f (x) 在区间[-1,3]上的图形为
O
第 3 页 共 142 页
-2 -1 0
23 x
则函数 F (x) x f (t)dt 为() 0 f (x)
n 1
n 1
(方法 2)反例:对 A 取 an bn (1)n
1 n
,对
B
取 an
bn
1 n
,对
D
取 an
bn
1 n
。
(5)设
a1
,
a2
,
a3
是
3
维向量空间
R3
的一组基,则由基
a1
,
1 2
a2
,
1 3
a3
到基
a1 a2, a2 a3, a3 a1 的过渡矩阵为()
1
(A)
2
0
0 2 3
D I4.
【答案】A.
【 详 解 】 D2, D4 关 于 x 轴 对 称 , 而 被 积 函 数 y cos x 是 关 于 y 的 奇 函 数 , 所 以
I2 I4 =0; D1, D3 两区域关于 y 轴对称,被积函数 y cos x 是关于 x 的偶函数,由积分对称
性和保号性可知 I1 2
x (2,3) 时, f (x) 0, F (x) 为常值函数。正确选项为 D.
(4)设有两个数列{an},{bn}
,若
lim
n
an
0
2009数模试题与答案
华南农业大学期末考试试卷(A 卷)2009学年第二学期 考试科目: 数学模型考试类型:(闭卷) 考试时间: 120分钟学号 B 姓名 年级专业题号 1 2 3 4 5 6 7 8 9 总分 得分 评阅人1、 (13分)设已知某正方形板材边长20cm ,现将之加工出半径为1cm 的圆盘,请对下面给出的两种排列方法,写出能加工出的尽可能多的圆盘数。
(1) 排列1:圆盘中心按正方形排列(如右图)的尽可能多的圆盘数。
(4分)解:圆盘总数:202010022⨯= 排列2:圆盘中心按六角形排列(如右图)的尽可能多的圆盘数。
(4分) 解:行数:1113+=⎢⎣圆盘总数:20111110522-⨯+=(2) 设计出不同于(1)(2)的方案,且加工出的圆盘更多。
(5分)解:前三行正方形,后八行六角形,圆盘总数为106(此题考虑的是当两种方案当两种方案被提出的时候,但仍需改进的时候,应该考虑这两者的综合是否可行,如果可行,则给出方案。
)2、 (10分)在举重比赛中,运动员在高度和体重方面差别很大,请就下面两种假设,建立一个举重能力和体重之间关系的模型: (1) 假设肌肉的强度和其横截面的面积成比例。
5分(2) 假定体重中有一部分是与成年人的尺寸无关,请给出一个改进模型。
5分 解:设体重w (千克)与举重成绩y (千克) (1) 由于肌肉强度(I)与其横截面积(S)成比例,所以 y ∝I ∝S设h 为个人身高,又横截面积正比于身高的平方,则S ∝ h2再体重正比于身高的三次方,则w ∝ h3 故举重能力和体重之间关系的模型为: (2) 体重中与成年人尺寸无关的重量为a, 则一个最粗略的模型为更好的模型: 得分得分23y kw =23()y k w a =-()y k w a γ=-3、 (10分)在超币购物时你压意到大包发商品比小包装面品便宜这种现象了吗?比如洁银牙膏50g 装的每支1.50元,120g 装的每支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。
2009数学建模试题与答案
华南农业大学期末考试试卷(A卷)2009学年第二学期考试科目:数学模型考试类型:(闭卷)考试时间:120分钟学号姓名年级专业1、(13分)设已知某正方形板材边长20cm,现将之加工出半径为1cm的圆盘,请对下面给出的两种排列方法,写出能加工出的尽可能多的圆盘数。
(1)排列1:圆盘中心按正方形排列(如右图)的尽可能多的圆盘数。
(4分)解:圆盘总数:202010022⨯=排列2:圆盘中心按六角形排列(如右图)的尽可能多的圆盘数。
(4分)解:行数:111+=圆盘总数:20111110522-⨯+=(2)设计出不同于(1)(2)的方案,且加工出的圆盘更多。
(5分)解:前三行正方形,后八行六角形,圆盘总数为106(此题考虑的是当两种方案当两种方案被提出的时候,但仍需改进的时候,应该考虑这两者的综合是否可行,如果可行,则给出方案。
)2、(10分)在举重比赛中,运动员在高度和体重方面差别很大,请就下面两种假设,建立一个举重能力和体重之间关系的模型:(1)假设肌肉的强度和其横截面的面积成比例。
5分(2)假定体重中有一部分是与成年人的尺寸无关,请给出一个改进模型。
5分解:设体重w(千克)与举重成绩y (千克)(1)由于肌肉强度(I)与其横截面积(S)成比例,所以y∝I∝S设h为个人身高,又横截面积正比于身高的平方,则S ∝ h2再体重正比于身高的三次方,则w ∝ h3(2)a, 则一个最粗略的模型为更好的模型:()y k w aγ=-3、 (10分)在超币购物时你压意到大包发商品比小包装面品便宜这种现象了吗?比如洁银牙膏50g 装的每支1.50元,120g 装的每支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)请写出商品价恪c 与商品重量w 的关系,其中价格由生产成本、包装成本和其它成本等决定,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。
(5分) (2)给出单位重量价格c与w 的关系,并解释。
2009考研数学(二)真题及参考答案
2009年研究生入学统一考试数学二试题与解析一、选择题:1~8小题,每小题4分,共32分.下列每题给出的四个选项中,只有一个选项是符合题目要求的.请将所选项前的字母填在答题纸指定位置上.(1)函数()3sin x x f x nx-=的可去间断点的个数为( )()A 1.()B 2. ()C 3.()D 无穷多个.(2)当0x →时,()sin f x x ax =-与()()2ln 1g x x bx =-是等价无穷小,则( )()A 11,6a b ==-.()B 11,6a b ==. ()C 11,6a b =-=-. ()D 11,6a b =-=(3)设函数(),z f x y =的全微分为dz xdx ydy =+,则点()0,0( )()A 不是(),f x y 的连续点. ()B 不是(),f x y 的极值点. ()C 是(),f x y 的极大值点. ()D 是(),f x y 的极小值点.(4)设函数(),f x y 连续,则()()222411,,yxydx f x y dy dy f x y dx -+=⎰⎰⎰⎰( )()A ()2411,xdx f x y dy -⎰⎰. ()B ()241,xxdx f x y dy -⎰⎰.()C ()2411,ydy f x y dx -⎰⎰.()D .()221,y dy f x y dx ⎰⎰(5)若()f x ''不变号,且曲线()y f x =在点()1,1上的曲率圆为222x y +=,则()f x 在区间()1,2内( )()A 有极值点,无零点. ()B 无极值点,有零点.()C 有极值点,有零点. ()D 无极值点,无零点.(6)设函数()y f x =在区间[]1,3-上的图形为1 ()f x -2 0 2 3x-1O则函数()()0xF x f t dt =⎰的图形为( )()A .()B .()C .()D .(7)设A ,B 均为2阶矩阵,**A B ,分别为A ,B 的伴随矩阵.若23A B ==,,则分块矩阵O A B O ⎛⎫⎪⎝⎭的伴随矩阵为( )()A .**32O B A O ⎛⎫⎪⎝⎭()B .**23OB A O ⎛⎫⎪⎝⎭ ()C .**32O A BO ⎛⎫ ⎪⎝⎭()D .**23O A BO ⎛⎫⎪⎝⎭(8)设A P ,均为3阶矩阵,TP 为P 的转置矩阵,且100010002T P AP ⎛⎫ ⎪= ⎪ ⎪⎝⎭,若1231223P Q ααααααα==+(,,),(,,),则TQ AQ 为( ) ()A .210110002⎛⎫⎪⎪ ⎪⎝⎭()B .110120002⎛⎫⎪⎪ ⎪⎝⎭()f x 0 2 3x1 -2-11()f x 02 3x1 -1 1()f x 02 3x1 -2-11()f x 0 2 3x1 -2 -11()C .200010002⎛⎫⎪⎪ ⎪⎝⎭()D .100020002⎛⎫⎪⎪ ⎪⎝⎭二、填空题:9-14小题,每小题4分,共24分.请将答案写在答题纸指定位置上.(9)曲线2221-x=0ln(2)u t e du y t t -⎧⎪⎨⎪=-⎩⎰在(0,0)处的切线方程为 . (10)已知+1k xe dx ∞=-∞⎰,则k = .(11)1n lime sin x nxdx -→∞=⎰.(12)设()y y x =是由方程xy 1ye x +=+确定的隐函数,则22x yx=∂=∂ .(13)函数2x y x =在区间(]01,上的最小值为 .(14)设αβ,为3维列向量,T β为β的转置,若矩阵T αβ相似于200000000⎛⎫⎪⎪ ⎪⎝⎭,则T =βα .三、解答题:15-23小题,共94分.请将解答写在答题纸指定的位置上.解答应写出文字说明、证明过程或演算步骤.(15)(本题满分9分)求极限()[]401cos ln(1tan )limsin x x x x x→--+.(16)(本题满分10 分) 计算不定积分1ln(1)xdx x++⎰(0)x >. (17)(本题满分10分)设(),,z f x y x y xy =+-,其中f 具有2阶连续偏导数,求dz 与2z x y∂∂∂.(18)(本题满分10分)设非负函数()y y x = ()0x ≥满足微分方程20xy y '''-+=,当曲线()y y x = 过原点时,其与直线1x =及0y =围成平面区域D 的面积为2,求D 绕y 轴旋转所得旋转体体积. (19)(本题满分10分)计算二重积分()Dx y dxdy -⎰⎰,其中()()(){}22,112,D x y x y y x =-+-≤≥.(20)(本题满分12分)设()y y x =是区间-ππ(,)内过点-22ππ(,)的光滑曲线,当-0x π<<时,曲线上任一点处的法线都过原点,当0x π≤<时,函数()y x 满足0y y x ''++=.求()y x 的表达式. (21)(本题满分11分)(Ⅰ)证明拉格朗日中值定理:若函数()f x 在[],a b 上连续,在(),a b 可导,则存在(),a b ξ∈,使得()()()()f b f a f b a ξ'-=-;(Ⅱ)证明:若函数()f x 在0x =处连续,在()()0,0δδ>内可导,且()0lim x f x A +→'=,则()0f +'存在,且()0f A +'=.(22)(本题满分11分设111111042A --⎛⎫ ⎪=- ⎪ ⎪--⎝⎭,1112ξ-⎛⎫⎪= ⎪ ⎪-⎝⎭. (Ⅰ)求满足22131,A A ξξξξ==的所有向量23,ξξ;(Ⅱ)对(Ⅰ)中的任一向量23,ξξ,证明:123,,ξξξ线性无关.(23)(本题满分11分)设二次型()()2221231231323,,122f x x x ax ax a x x x x x =++-+-(Ⅰ)求二次型f 的矩阵的所有特征值;(Ⅱ)若二次型f 的规范形为2212y y +,求a 的值.2009年全国硕士研究生入学统一考试数学二试题答案一、选择题:1~8小题,每小题4分,共32分.下列每题给出的四个选项中,只有一个选项是符合题目要求的.请将所选项前的字母填在答题纸指定位置上.(1)函数()3sin x x f x nx-=的可去间断点的个数为( )()A 1.()B 2. ()C 3.()D 无穷多个.【答案】C 【解析】()3s i n x x f x xπ-=则当x 取任何整数时,()f x 均无意义故()f x 的间断点有无穷多个,但可去间断点为极限存在的点,故应是30x x -=的解1,2,30,1x =±320032113211131lim lim sin cos 132lim lim sin cos 132lim lim sin cos x x x x x x x x x x x x x x x x x x x x x ππππππππππππ→→→→→-→---==--==--== 故可去间断点为3个,即0,1±(2)当0x →时,()sin f x x ax =-与()()2ln 1g x x bx =-是等价无穷小,则( )()A 11,6a b ==-. ()B 11,6a b ==. ()C 11,6a b =-=-. ()D 11,6a b =-=. 【答案】A【解析】2()sin ,()(1)f x x ax g x x ln bx =-=-为等价无穷小,则222200000()sin sin 1cos sin lim lim lim lim lim ()ln(1)()36x x x x x f x x ax x ax a ax a axg x x bx x bx bx bx→→→→→---==-⋅---洛洛230sin lim 166x a ax a b b axa→==-=-⋅ 36a b ∴=- 故排除,B C . 另外201cos lim3x a axbx→--存在,蕴含了1cos 0a ax -→()0x →故 1.a =排D .所以本题选A.(3)设函数(),z f x y =的全微分为dz xdx ydy =+,则点()0,0( )()A 不是(),f x y 的连续点. ()B 不是(),f x y 的极值点. ()C 是(),f x y 的极大值点. ()D 是(),f x y 的极小值点.【答案】 D【解析】因dz xdx ydy =+可得,z zx y x y∂∂==∂∂ 2222221,0,1z z z zA B C x x y y x y∂∂∂∂== === ==∂∂∂∂∂∂又在(0,0)处,0,0z zx y∂∂==∂∂ 210AC B -=>故(0,0)为函数(,)z f x y =的一个极小值点.(4)设函数(),f x y 连续,则()()222411,,yxydx f x y dy dy f x y dx -+=⎰⎰⎰⎰( )()A ()2411,xdx f x y dy -⎰⎰. ()B ()241,xxdx f x y dy -⎰⎰.()C ()2411,ydy f x y dx -⎰⎰.()D .()221,y dy f x y dx ⎰⎰【答案】C 【解析】222211(,)(,)xxdx f x y dy dy f x y dx +⎰⎰⎰⎰的积分区域为两部分:{}1(,)12,2D x y x x y =≤≤≤≤,{}2(,)12,4D x y y y x y =≤≤≤≤-将其写成一块{}(,)12,14D x y y x y =≤≤≤≤- 故二重积分可以表示为2411(,)ydy f x y dx -⎰⎰,故答案为C.(5)若()f x ''不变号,且曲线()y f x =在点()1,1上的曲率圆为222x y +=,则()f x 在区间()1,2内( )()A 有极值点,无零点. ()B 无极值点,有零点.()C 有极值点,有零点. ()D 无极值点,无零点.【答案】 B【解析】由题意可知,()f x 是一个凸函数,即''()0f x <,且在点(1,1)处的曲率322|''|12(1('))y y ρ==+,而'(1)1f =-,由此可得,''(1)2f =-在[1,2] 上,'()'(1)10f x f ≤=-<,即()f x 单调减少,没有极值点. 对于(2)(1)'()1(1,2)f f f ζζ-=<- , ∈ , (拉格朗日中值定理)(2)0f ∴ <而 (1)10f =>由零点定理知,在[1,2] 上,()f x 有零点. 故应选(B ). (6)设函数()y f x =在区间[]1,3-上的图形为则函数()()0xF x f t dt =⎰的图形为( )1 ()f x -2 0 2 3x-1O()A .()B .()C .()D .【答案】D【解析】此题为定积分的应用知识考核,由()y f x =的图形可见,其图像与x 轴及y 轴、0x x =所围的图形的代数面积为所求函数()F x ,从而可得出几个方面的特征: ①[]0,1x ∈时,()0F x ≤,且单调递减. ②[]1,2x ∈时,()F x 单调递增. ③[]2,3x ∈时,()F x 为常函数.④[]1,0x ∈-时,()0F x ≤为线性函数,单调递增. ⑤由于F(x)为连续函数结合这些特点,可见正确选项为D .(7)设A ,B 均为2阶矩阵,**A B ,分别为A ,B 的伴随矩阵.若23A B ==,,则分块矩阵O A B O ⎛⎫⎪⎝⎭的伴随矩阵为( )()A .**32O B A O ⎛⎫⎪⎝⎭()B .**23OB A O ⎛⎫⎪⎝⎭ ()C .**32O A BO ⎛⎫ ⎪⎝⎭()D .**23O A BO ⎛⎫⎪⎝⎭()f x 0 2 3x1 -2-11()f x 02 3x1 -1 1()f x 02 3x1 -2-11()f x 0 2 3x1 -2 -11【答案】 B【解析】根据CC C E *=若111,C C C CC C*--*==分块矩阵00A B ⎛⎫⎪⎝⎭的行列式22012360A AB B⨯=-=⨯=()即分块矩阵可逆 111100066000100B BA A AB B BBAA A**---*⎛⎫ ⎪⎛⎫⎛⎫⎛⎫ ⎪=== ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭⎪⎝⎭10023613002BB AA ****⎛⎫ ⎪⎛⎫== ⎪ ⎪ ⎪⎝⎭⎪⎝⎭(8)设A P ,均为3阶矩阵,TP 为P 的转置矩阵,且100010002T P AP ⎛⎫ ⎪= ⎪ ⎪⎝⎭,若1231223P Q ααααααα==+(,,),(,,),则TQ AQ 为( ) ()A .210110002⎛⎫⎪⎪ ⎪⎝⎭()B .110120002⎛⎫⎪⎪ ⎪⎝⎭()C .200010002⎛⎫⎪⎪ ⎪⎝⎭()D .100020002⎛⎫⎪⎪ ⎪⎝⎭【答案】 A【解析】122312312312100(,,)(,,)110(,,)(1)001Q E αααααααααα⎡⎤⎢⎥=+==⎢⎥⎢⎥⎣⎦,即:12121212122112(1)[(1)][(1)](1)[](1)100(1)010(1)002110100100210010010110110001002001002T T TT T Q PE Q AQ PE A PE E P AP E E E ===⎡⎤⎢⎥=⎢⎥⎢⎥⎣⎦⎡⎤⎡⎤⎡⎤⎡⎤⎢⎥⎢⎥⎢⎥⎢⎥==⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎢⎥⎣⎦⎣⎦⎣⎦⎣⎦二、填空题:9-14小题,每小题4分,共24分.请将答案写在答题纸指定位置上.(9)曲线2221-x=0ln(2)u t e du y t t -⎧⎪⎨⎪=-⎩⎰在(0,0)处的切线方程为 . 【答案】2y x =【解析】221222ln(2)22t dy t t t t dt t ==--⋅=--2(1)1(1)1t t dxe dt --==⋅-=- 所以 2dy dx= 所以 切线方程为2y x =.(10)已知+1k xe dx ∞=-∞⎰,则k = .【答案】2-【解析】1122lim bk xkxkxb e dx e dx e k +∞+∞-∞→+∞===⎰⎰因为极限存在所以0k <210k=-2k =-(11)1n lime sin x nxdx -→∞=⎰.【答案】0【解析】令sin sin cos x x xn I e nxdx e nx n e nxdx ---==-+⎰⎰2sin cos x xn e nx nenx n I --=---所以2cos sin 1xn n nx nx I e C n -+=-++即11020cos sin lim sin lim()1xx n n n nx nx e nxdx e n --→∞→∞+=-+⎰ 122cos sin lim()110n n n n ne n n -→∞+=-+++= (12)设()y y x =是由方程xy 1ye x +=+确定的隐函数,则22x yx=∂=∂ .【答案】3-【解析】对方程xy 1y e x +=+两边关于x 求导有''1y y xy y e ++=,得'1yyy x e -=+ 对''1y y xy y e ++=再次求导可得''''''22()0y y y xy y e y e +++=,得''2''2()yyy y e y x e +=-+ (*)当0x =时,0y =,'(0)0101y e -==,代入(*)得 ''20''032(0)((0))(0)(21)3(0)y y e y e +=-=-+=-+(13)函数2x y x =在区间(]01,上的最小值为 . 【答案】2ee-【解析】因为()22ln 2xy xx '=+,令0y '=得驻点为1x e =.又()22222ln 2xxy x x x x ''=++⋅,得21120e y e e -+⎛⎫''=> ⎪⎝⎭,故1x e=为2xy x =的极小值点,此时2e y e -=,又当10,x e ⎛⎫∈ ⎪⎝⎭时,()0y x '<;1,1x e ⎛⎤∈ ⎥⎝⎦时,()0y x '>,故y 在10,e ⎛⎫ ⎪⎝⎭上递减,在1,1e ⎛⎫ ⎪⎝⎭上递增.而()11y =,()()002022ln limlim11lim 222ln 00lim lim 1x x x xx x xx xxx x x y x e eee++→→+→++--+→→======,所以2xy x =在区间(]01,上的最小值为21ey e e -⎛⎫= ⎪⎝⎭.(14)设αβ,为3维列向量,T β为β的转置,若矩阵T αβ相似于200000000⎛⎫ ⎪⎪ ⎪⎝⎭,则T =βα .【答案】2【解析】因为T αβ相似于200000000⎛⎫⎪⎪ ⎪⎝⎭,根据相似矩阵有相同的特征值,得到T αβ得特征值是2,0,0而T βα是一个常数,是矩阵T αβ的对角元素之和,则T 2002βα=++=三、解答题:15-23小题,共94分.请将解答写在答题纸指定的位置上.解答应写出文字说明、证明过程或演算步骤.(15)(本题满分9分)求极限()[]401cos ln(1tan )limsin x x x x x→--+.【解析】()[][]244001ln(1tan )1cos ln(1tan )2lim limsin sin x x x x x x x x x x→→-+--+= 22201ln(1tan )lim 2sin sin x x x x x x→-+=201ln(1tan )1lim 2sin 4x x x x →-+== (16)(本题满分10 分) 计算不定积分1ln(1)xdx x++⎰(0)x >. 【解析】 令1x t x+=得22212,1(1)tdtx dx t t -= =-- 22211ln(1)ln(1)1ln(1)11111x dx t d x t t dt t t t ++=+-+=---+⎰⎰⎰而22111112()11411(1)111ln(1)ln(1)2441dt dtt t t t t t t C t =---+-++--++++⎰⎰所以221ln(1)111ln(1)ln 1412(1)111ln(1)ln(1)2211111ln(1)ln(1)222x t t dx C x t t t x xx x x C x x x x x x x x x x C x ++++=+-+--++=++++-++++=+++++-++⎰ (17)(本题满分10分)设(),,z f x y x y xy =+-,其中f 具有2阶连续偏导数,求dz 与2zx y∂∂∂.【解析】123123zf f yf x zf f xf y∂'''=++∂∂'''=-+∂1231232111213212223331323331122331323()()1(1)1(1)[1(1)]()()z z dz dx dy x yf f yf dx f f xf dyzf f f x f f f x f y f f f x x yf f f xyf x y f x y f ∂∂∴=+∂∂''''''=+++-+∂'''''''''''''''''''=⋅+⋅-+⋅+⋅+⋅-+⋅++⋅+⋅-+⋅∂∂'''''''''''=+-++++-(18)(本题满分10分)设非负函数()y y x = ()0x ≥满足微分方程20xy y '''-+=,当曲线()y y x = 过原点时,其与直线1x =及0y =围成平面区域D 的面积为2,求D 绕y 轴旋转所得旋转体体积. 【解析】解微分方程20xy y '''-+=得其通解212122,y C x C x C C =++其中,为任意常数又因为()y y x =通过原点时与直线1x =及0y =围成平面区域的面积为2,于是可得10C =1112232220002()(2)()133C C y x dx x C x dx x x ==+=+=+⎰⎰从而23C =于是,所求非负函数223(0)y x x x =+ ≥又由223y x x =+ 可得,在第一象限曲线()y f x =表示为1131)3x y =+-(于是D 围绕y 轴旋转所得旋转体的体积为15V V π=-,其中552210051(131)9(23213)93918V x dy y dyy y dy ππππ==⋅+-=+-+=⎰⎰⎰395117518186V ππππ=-==. (19)(本题满分10分)计算二重积分()Dx y dxdy -⎰⎰,其中()()(){}22,112,D x y x y y x =-+-≤≥.【解析】由22(1)(1)2x y -+-≤得2(sin cos )r θθ≤+,32(sin cos )4()(cos sin )04Dx y dxdy d r r rdr πθθθθθπ+∴-=-⎰⎰⎰⎰332(sin cos )14(cos sin )034r d πθθθθθπ⎡+⎤=-⋅⎢⎥⎣⎦⎰ 2384(cos sin )(sin cos )(sin cos )34d πθθθθθθθπ=-⋅+⋅+⎰ 3384(cos sin )(sin cos )34d πθθθθθπ=-⋅+⎰3344438814(sin cos )(sin cos )(sin cos )3344d πππθθθθθθπ=++=⨯+⎰83=-.(20)(本题满分12分)设()y y x =是区间-ππ(,)内过点-22ππ(,)的光滑曲线,当-0x π<<时,曲线上任一点处的法线都过原点,当0x π≤<时,函数()y x 满足0y y x ''++=.求()y x 的表达式.【解析】由题意,当0x π-<<时,'xy y =-,即ydy xdx =-,得22y x c =-+, 又()22y ππ-=代入22y x c =-+得2c π=,从而有222x y π+=当0x π≤<时,''0y y x ++=得 ''0y y += 的通解为*12cos sin y c x c x =+ 令解为1y Ax b =+,则有00Ax b x +++=,得1,0A b =-=, 故1y x =-,得''0y y x ++=的通解为12cos sin y c x c x x =+- 由于()y y x =是(,)ππ-内的光滑曲线,故y 在0x =处连续于是由1(0),(0)y y c π-=± += ,故1c π=±时,()y y x =在0x =处连续 又当 0x π-<<时,有22'0x y y +⋅=,得'(0)0xy y-=-=, 当0x π≤<时,有12'sin cos 1y c x c x =-+-,得2'(0)1y c +=- 由'(0)'(0)y y -+=得210c -=,即 21c =故 ()y y x =的表达式为22,0cos sin ,0x x y x x x x ππππ⎧⎪-- -<<=⎨-+-≤<⎪⎩或22,0cos sin ,0x x y x x x x ππππ⎧⎪- -<<=⎨+-≤<⎪⎩,又过点,22ππ⎛⎫- ⎪⎝⎭,所以22,0cos sin ,0x x y x x x x ππππ⎧⎪- -<<=⎨+-≤<⎪⎩.(21)(本题满分11分)(Ⅰ)证明拉格朗日中值定理:若函数()f x 在[],a b 上连续,在(),a b 可导,则存在(),a b ξ∈,使得()()()()f b f a f b a ξ'-=-;(Ⅱ)证明:若函数()f x 在0x =处连续,在()()0,0δδ>内可导,且()0lim x f x A +→'=,则()0f +'存在,且()0f A +'=.【解析】(Ⅰ)作辅助函数()()()()()()f b f a x f x f a x a b aϕ-=----,易验证()x ϕ满足:()()a b ϕϕ=;()x ϕ在闭区间[],a b 上连续,在开区间(),a b 内可导,且''()()()()f b f a x f x b aϕ-=--.根据罗尔定理,可得在(),a b 内至少有一点ξ,使'()0ϕξ=,即'()f ξ'()()0,()()()()f b f a f b f a f b a b aξ--=∴-=--(Ⅱ)任取0(0,)x δ∈,则函数()f x 满足;在闭区间[]00,x 上连续,开区间()00,x 内可导,从而有拉格朗日中值定理可得:存在()()000,0,x x ξδ∈⊂,使得()0'()(0)x f x f fx ξ-=-……()* 又由于()'lim x f x A +→=,对上式(*式)两边取00x +→时的极限可得:()()000000'''0000()00lim lim ()lim ()0x x x x x f x f f f f A x ξξξ++++→→→-====- 故'(0)f +存在,且'(0)f A +=.(22)(本题满分11分设111111042A --⎛⎫ ⎪=- ⎪ ⎪--⎝⎭,1112ξ-⎛⎫ ⎪= ⎪ ⎪-⎝⎭(Ⅰ)求满足22131,A A ξξξξ==的所有向量23,ξξ;(Ⅱ)对(Ⅰ)中的任一向量23,ξξ,证明:123,,ξξξ线性无关. 【解析】(Ⅰ)解方程21A ξξ=()1111111111111,111100000211042202110000A ξ---------⎛⎫⎛⎫⎛⎫ ⎪ ⎪ ⎪=-→→ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪---⎝⎭⎝⎭⎝⎭()2r A =故有一个自由变量,令32x =,由0Ax =解得,211,1x x =-= 求特解,令120x x ==,得31x =故21101021k ξ⎛⎫⎛⎫ ⎪ ⎪=-+ ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭,其中1k 为任意常数解方程231A ξξ=2220220440A ⎛⎫ ⎪=-- ⎪ ⎪⎝⎭()21111022012,2201000044020000A ξ-⎛⎫ ⎪-⎛⎫ ⎪ ⎪=--→ ⎪ ⎪ ⎪ ⎪⎝⎭ ⎪⎝⎭故有两个自由变量,令21x =-,由20A x =得131,0x x ==求特解21200η⎛⎫ ⎪ ⎪= ⎪ ⎪⎪⎝⎭故 321121000k ξ⎛⎫⎪⎛⎫ ⎪⎪=-+ ⎪ ⎪⎪ ⎪⎝⎭ ⎪⎝⎭ ,其中2k 为任意常数.(Ⅱ)证明:由于12121212122111121112(21)()2()(21)222210k k k k k k k k k k k k k -+--=+++-+-+-+102=≠ 故123,,ξξξ 线性无关.(23)(本题满分11分)设二次型()()2221231231323,,122f x x x ax ax a x x x x x =++-+- (Ⅰ)求二次型f 的矩阵的所有特征值;(Ⅱ)若二次型f 的规范形为2212y y +,求a 的值. 【解析】(Ⅰ) 0101111a A aa ⎛⎫ ⎪=- ⎪ ⎪--⎝⎭0110||01()1111111aaaE A aa a a λλλλλλλλ-----=-=---+---+222()[()(1)1][0()]()[()(1)2]()[22]19(){[(12)]}24()(2)(1)a a a a a a a a a a a a a a a a a λλλλλλλλλλλλλλλλ=---+--+-=---+-=--++--=-+--=--+--123,2,1a a a λλλ∴==-=+(Ⅱ) 若规范形为2212y y +,说明有两个特征值为正,一个为0.则 1) 若10a λ==,则 220λ=-< ,31λ= ,不符题意2) 若20λ= ,即2a =,则120λ=>,330λ=>,符合3) 若30λ= ,即1a =-,则110λ=-< ,230λ=-<,不符题意 综上所述,故2a =.。
2009年全国硕士研究生入学考试数学二真题及答案
y y x 0 。求 y(x)的表达式。
(21)(本题满分 11 分)(I)证明拉格朗日中值定理:若函数 f (x) 在[a,b]上连续,在(a,b)
可导,则存在 (a,b) ,使得 f (b) f (a) f ( )(b a) 。(II)证明:若函数 f (x) 在 x=0
阵
0 B
A 0
的伴随矩阵为()
(A)
0 2 A
3B
0
(B)
0 3 A
2B
0
பைடு நூலகம்(C)
0 2B
3A
0
(D)
0 3B
2 A
0
100
(8)设
A,P
均为
3
阶矩阵,
PT
为
P
的转置矩阵,且
1
x
1
y
A
2
dx
4x f x, y dy
1
1
C
2
dy
4y f x, y dx
1
1
B
2
dx
4x f x, y dy
1
x
D
2
1
2
dyy
f
x,
y dx
【答案】 C
2
2
2
2
【解析】 dx f (x, y)dy dy f (x, y)dx 的积分区域为两部分:
sin x
A 1 B 2 C 3 D 无穷多个
【答案】 C
【解析】由于 f x x x3 ,则当 x 取任何整数时, f x 均无意义.
华中农业大学食品化学2009年真题
华中农业大学二○○九年硕士研究生入学考试课程名称:食品化学一、名词解释题(每小题2分,共20分)1.等温吸着曲线2.脂肪同质多晶现象3.嗅感4.乳化容量5.香味增强剂6.氧合作用7.疏水相互作用8.蛋白质的二级结构9.维生素原10.Modified Starch二、填空题(每题1分,共20分)1.在食品中水的存在形式有和游离水两种,其中对食品的保存性能影响最大的是。
2.天然蛋白质中的氨基酸均为型结构,常见的氨基酸一般含有一个氨基和一个。
3.油脂的熔点也与油脂的晶体结构有关:油脂的晶型分别是,它们密度大小的顺序是。
4.下述多糖、蛋白质所形成的凝胶是热可逆的有,在形成凝胶时需要钙离子。
血清蛋白,大豆蛋白,酪蛋白,明胶,果胶,海藻酸钠,琼脂,卵清蛋白,卡拉胶,改性纤维素。
5.在天然色素中,叶绿素为绿色可以溶于,花青苷是水溶性的,一般为色或者蓝色。
6.苯甲酸在性pH条件下具有较强的抑菌能力,它同山梨酸之间存在作用。
7.常见的食品有害成分中,胰蛋白酶抑制物存在于中,而龙葵素则常常能够在发芽的土豆中能检测出。
8.在蛋白质的功能性质中,水合性质是指蛋白质同的作用。
剪切稀释则是指在条件下蛋白质溶液黏度的改变。
9.直链淀粉虽然在冷水中不溶,加热时会产生现象,但经过一段时间的放置会发生现象。
10.色淀是由合成色素和制成的,色淀在水中的溶解行为是。
11.LD50的中文意思是。
一种食品添加剂的LD50为2400mg/kg,另一种食品添加剂的LD50为500mg/kg,则急性毒性较强的为。
12.水溶性维生素中热稳定性最差的是,总体上看最稳定的是。
13.HBL为4的乳化剂适用于型的乳化体系,而HBL为13的乳化剂适用于型的乳化体系。
14.在油脂加工中,脱胶处理除去的是,碱精炼处理除去的是。
15.在发生美拉德反应时,与果糖相比,葡萄糖的反应性果糖,赖氨酸的反应性是所有氨基酸中。
16.在发生美拉德反应时高温下的反应速度比低温下的速度,添加可以有效地抑制反应进行。
2009年全国硕士研究生入学统一考试真题加答案
2009年全国硕士研究生入学统一考试英语试题Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. (10 points)Research on animal intelligence always makes me wonder just how smart humans are.1 the fruit-fly experiments described in Carl Zimmer‘s piece in the Science Times on Tuesday. Fruit flies who were taught to be smarter than the average fruit fly 2 to live shorter lives. This suggests that 3 bulbs burn longer, that there is an 4 in not being too terrifically bright.Intelligence, it 5 out, is a high-priced option. It takes more upkeep, burns more fuel and is slow 6 the starting line because it depends on learning — a gradual 7 — instead of instinct. Plenty of other species are able to learn, and one of the things they‘ve apparently learned is when to 8 .Is there an adaptive value to 9 intelligence? That‘s the question behind this new research. I like it. Instead of casting a wistful glance 10 at all the species we‘ve left in the dust I.Q.-wise, it implicitly asks what the real11 of our own intelligence might be. This is 12 the mind of every animal I‘ve ever met.Research on animal intelligence also makes me wonder what experiments animals would 13 on humans if they had the chance. Every cat with an owner, 14 , is running a small-scale study in operant conditioning. we believe that 15 animals ran the labs, they would test us to 16 the limits of our patience, our faithfulness, our memory for terrain. They would try to decide what intelligence in humans is really 17 , not merely how much of it there is. 18 , they would hope to study a 19 question: Are humans actually aware of the world they live in? 20 the results are inconclusive.1. [A] Suppose [B] Consider [C] Observe [D] Imagine2. [A] tended [B] feared [C] happened [D] threatened3. [A] thinner [B] stabler [C] lighter [D] dimmer4. [A] tendency [B] advantage [C] inclination [D] priority5. [A] insists on [B] sums up [C] turns out [D] puts forward6. [A] off [B] behind [C] over [D] along7. [A] incredible [B] spontaneous [C]inevitable [D] gradual8. [A] fight [B] doubt [C] stop [D] think19. [A] invisible [B] limited [C] indefinite [D] different10. [A] upward [B] forward [C] afterward [D] backward11. [A] features [B] influences [C] results [D] costs12. [A] outside [B] on [C] by [D] across13. [A] deliver [B] carry [C] perform [D] apply14. [A] by chance [B] in contrast [C] as usual [D] for instance15. [A] if [B] unless [C] as [D] lest16. [A] moderate [B] overcome [C] determine [D] reach17. [A] at [B] for [C] after [D] with18. [A] Above all [B] After all [C] However [D] Otherwise19. [A] fundamental [B] comprehensive [C] equivalent [D] hostile20. [A] By accident [B] In time [C] So far [D] Better stillSection II Reading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1. (40 points)Text1Habits are a funny thing. We reach for them mindlessly, setting our brains on auto-pilot and relaxing into the unconscious comfort of familiar routine. ―Not choice, but habit rules the unreflecting herd,‖ William Wordsworth said in the 19th century. In the ever-changing 21st century, even the word ―habit‖ carries a ne gative connotation.So it seems antithetical to talk about habits in the same context as creativity and innovation. But brain researchers have discovered that when we consciously develop new habits, we create parallel synaptic paths, and even entirely new brain cells, that can jump our trains of thought onto new, innovative tracks.But don‘t bother trying to kill off old habits; once those ruts of procedure are worn into the hippocampus, they‘re there to stay. Instead, the new habits we deliberately ingrain into ourselves create parallel pathways that can bypass those old roads.―The first thing needed for innovation is a fascination with wonder,‖ says Dawna Markova, author of ―The Open Mind‖ and an executive change consultant for Professional Thinking Part ners. ―But we are taught instead to ‗decide,‘ just as our president calls himself ‗the Decider.‘‖ She adds, however, that ―to decide is to kill off all possibilities but one. A good innovational thinker is always exploring the many other possibilities.‖A ll of us work through problems in ways of which we‘re unaware, she says. Researchers in the late 1960 covered that humans are born with the capacity to2approach challenges in four primary ways: analytically, procedurally, relationally (or collaboratively) and innovatively. At puberty, however, the brain shuts down half of that capacity, preserving only those modes of thought that have seemed most valuable during the first decade or so of life.The current emphasis on standardized testing highlights analysis and procedure, meaning that few of us inherently use our innovative and collaborative modes of thought. ―This breaks the major rule in the American belief system — that anyone can do anything,‖ explains M. J. Ryan, author of the 2006 book ―This Year I Will...‖ and Ms. Markova‘s business partner. ―That‘s a lie that we have perpetuated, and it fosters commonness. Knowing what you‘re good at and doing even more of it creates excellence.‖ This is where developing new habits comes in.21. The view of Wordsworth habit is claimed by beingA. casualB. familiarC. mechanicalD. changeable.22. The researchers have discovered that the formation of habit can beA. predictedB. regulatedC. tracedD. guided23.‖ ruts‖(in li ne one, paragraph 3) has closest meaning toA. tracksB. seriesC. characteristicsD. connections24. Ms. Markova‘s comments suggest that the practice of standard testing ? A, prevents new habits form being formedB, no longer emphasizes commonnessC, maintains the inherent American thinking modelD, complies with the American belief system25. Ryan most probably agree thatA. ideas are born of a relaxing mindB. innovativeness could be taughtC. decisiveness derives from fantastic ideasD. curiosity activates creative mindsText 2It is a wise father that knows his own child, but today a man can boost his paternal (fatherly) wisdom –or at least confirm that he‘s the kid‘s dad. All he needs to do is shell our $30 for paternity testing kit (PTK) at his local drugstore – and another $120 to get the results.More than 60,000 people have purchased the PTKs since they first become available without prescriptions last years, according to Doug Fog, chief operating officer of Identigene, which makes the over-the-counter kits. More than two dozen companies sell DNA tests Directly to the public , ranging in price from a few hundred dollars to more than $2500.3Among the most popular : paternity and kinship testing , which adopted children can use to find their biological relatives and latest rage a many passionate genealogists-and supports businesses that offer to search for a family‘s geographic roots .Most tests require collecting cells by webbing saliva in the mouth and sending it to the company for testing. All tests require a potential candidate with whom to compare DNA.But some observers are skeptical, ―There is a kind of false precision being hawked by people claiming they are doing ancestry testing,‖ says Trey Duster, a New York University sociologist. He notes that each individual has many ancestors-numbering in the hundreds just a few centuries back. Yet most ancestry testing only considers a single lineage, either the Y chromosome inherited through men in a father‘s line or mito chondrial DNA, which a passed down only from mothers. This DNA can reveal genetic information about only one or two ancestors, even though, for example, just three generations back people also have six other great-grandparents or, four generations back, 14 other great-great-grandparents.Critics also argue that commercial genetic testing is only as good as the reference collections to which a sample is compared. Databases used by some companies don‘t rely on data collected systematically but rather lump together information from different research projects. This means that a DNA database may differ depending on the company that processes the results. In addition, the computer programs a company uses to estimate relationships may be patented and not subject to peer review or outside evaluation.26.In paragraphs 1 and 2 , the text shows PTK‘s ___________.[A]easy availability[B]flexibility in pricing[C] successful promotion[D] popularity with households27. PTK is used to __________.[A]locate one‘s b irth place[B]promote genetic research[C] identify parent-child kinship[D] choose children for adoption28. Skeptical observers believe that ancestry testing fails to__________.[A]trace distant ancestors[B] rebuild reliable bloodlines[C] fully use genetic information[D] achieve the claimed accuracy29. In the last paragraph ,a problem commercial genetic testing faces is __________.4[A]disorganized data collection[B] overlapping database building30. An appropriate title for the text is most likely to be__________.[A]Fors and Againsts of DNA testing[B] DNA testing and It‘s problems[C]DNA testing outside the lab[D] lies behind DNA testingText 3The relationship between formal education and economic growth in poor countries is widely misunderstood by economists and politicians alike progress in both area is undoubtedly necessary for the social, political and intellectual development of these and all other societies; however, the conventional view that education should be one of the very highest priorities for promoting rapid economic development in poor countries is wrong. We are fortunate that is it, because new educational systems there and putting enough people through them to improve economic performance would require two or three generations. The findings of a research institution have consistently shown that workers in all countries can be trained on the job to achieve radical higher productivity and, as a result, radically higher standards of living.Ironically, the first evidence for this idea appeared in the United States. Not long ago, with the country entering a recessing and Japan at its pre-bubble peak. The U.S. workforce was derided as poorly educated and one of primary cause of the poor U.S. economic performance. Japan was, and remains, the global leader in automotive-assembly productivity. Yet the research revealed that the U.S. factories of Honda Nissan, and Toyota achieved about 95 percent of the productivity of their Japanese countere pants a result of the training that U.S. workers received on the job.More recently, while examing housing construction, the researchers discovered that illiterate, non-English- speaking Mexican workers in Houston, Texas, consistently met best-practice labor productivity standards despite the complexity of the building industry‘s work.What is the real relationship between education and economic development? We have to suspect that continuing economic growth promotes the development of education even when governments don‘t force it. After all, that‘s how education got started. When our ancestors were hunters and gatherers 10,000 years ago, they didn‘t have time to wonder much about anything besides finding food. Only when humanity began to get its food in a more productive way was there time for other things.As education improved, humanity‘s productivity potential, they could in turn afford more education. This increasingly high level of education is probably a necessary, but not a sufficient, condition for the complex political systems required by advanced5economic performance. Thus poor countries might not be able to escape their poverty traps without political changes that may be possible only with broader formal education. A lack of formal education, however, doesn‘t const rain the ability of the developing world‘s workforce to substantially improve productivity for the forested future. On the contrary, constraints on improving productivity explain why education isn‘t developing more quickly there than it is.31. The author holds in paragraph 1 that the important of education in poor countries ___________.[A] is subject groundless doubts[B] has fallen victim of bias[C] is conventional downgraded[D] has been overestimated32. It is stated in paragraph 1 that construction of a new education system __________.[A]challenges economists and politicians[B]takes efforts of generations[C] demands priority from the government[D] requires sufficient labor force33.A major difference between the Japanese and U.S workforces is that __________.[A] the Japanese workforce is better disciplined[B] the Japanese workforce is more productive[C]the U.S workforce has a better education[D] ]the U.S workforce is more organize34. The author quotes the example of our ancestors to show that education emerged __________.[A] when people had enough time[B] prior to better ways of finding food[C] when people on longer went hung[D] as a result of pressure on government35. According to the last paragraph , development of education __________.[A] results directly from competitive environments[B] does not depend on economic performance[C] follows improved productivity[D] cannot afford political changesText 4The most thoroughly studied in the history of the new world are the ministers and political leaders of seventeenth-century New England. According to the standard history of American philosophy, nowhere else in colonial America was ―So much6important attached to intellectual pursuits ‖ Accord ing to many books and articles, New England‘s leaders established the basic themes and preoccupations of an unfolding, dominant Puritan tradition in American intellectual life.To take this approach to the New Englanders normally mean to start with the Puritans‘ theological innovations and their distinctive ideas about the church-important subjects that we may not neglect. But in keeping with our examination of southern intellectual life, we may consider the original Puritans as carriers of European culture adjusting to New world circumstances. The New England colonies were the scenes of important episodes in the pursuit of widely understood ideals of civility and virtuosity.The early settlers of Massachusetts Bay included men of impressive education and influence in England. `Besides the ninety or so learned ministers who came to Massachusetts church in the decade after 1629,There were political leaders like John Winthrop, an educated gentleman, lawyer, and official of the Crown before he journeyed to Boston. There men wrote and published extensively, reaching both New World and Old World audiences, and giving New England an atmosphere of intellectual earnestness.We should not forget , however, that most New Englanders were less well educated. While few crafts men or farmers, let alone dependents and servants, left literary compositions to be analyzed, The in thinking often had a traditional superstitions quality. A tailor named John Dane, who emigrated in the late 1630s, left an account of his reasons for leaving England that is filled with signs. sexual confusion, economic frustrations , and religious hope-all name together in a decisive moment when he opened the Bible, told his father the first line he saw would settle his fate, and read th e magical words: ―come out from among them, touch no unclean thing , and I will be your God and you shall be my people.‖ One wonders what Dane thought of the careful sermons explaining the Bible that he heard in puritan churched.Mean while , many se ttles had slighter religious commitments than Dane‘s, as one clergyman learned in confronting folk along the coast who mocked that they had not come to the New world for religion . ―Our main end was to catch fish. ‖36. The author notes that in the seventeenth-century New England___________.[A] Puritan tradition dominated political life.[B] intellectual interests were encouraged.[C] Politics benefited much from intellectual endeavors.[D] intellectual pursuits enjoyed a liberal environment.37. It is suggested in paragraph 2 that New Englanders__________.[A] experienced a comparatively peaceful early history.[B] brought with them the culture of the Old World[C] paid little attention to southern intellectual life[D] were obsessed with religious innovations738. The early ministers and political leaders in Massachusetts Bay__________.[A] were famous in the New World for their writings[B] gained increasing importance in religious affairs[C] abandoned high positions before coming to the New World[D] created a new intellectual atmosphere in New England39. The story of John Dane shows that less well-educated New Englanders were often __________.[A] influenced by superstitions[B] troubled with religious beliefs[C] puzzled by church sermons[D] frustrated with family earnings40. The text suggests that early settlers in New England__________.[A] were mostly engaged in political activities[B] were motivated by an illusory prospect[C] came from different backgrounds.[D] left few formal records for later referencePart BDirections:Directions: In the following text, some sentences have been removed. For Questions (41-45), choose the most suitable one from the list A-G to fit into each of the numbered blank. There are two extra choices, which do not fit in any of the gaps. Mark your answers on ANSWER SHEET 1. (10 points)Coinciding with the groundbreaking theory of biological evolution proposed by British naturalist Charles Darwin in the 1860s, British social philosopher Herbert Spencer put forward his own theory of biological and cultural evolution. Spencer argued that all worldly phenomena, including human societies, changed over time, advancing toward perfection. 41.____________.American social scientist Lewis Henry Morgan introduced another theory of cultural evolution in the late 1800s. Morgan, along with Tylor, was one of the founders of modern anthropology. In his work, he attempted to show how all aspects of culture changed together in the evolution of societies.42._____________.In the early 1900s in North America, German-born American anthropologist Franz Boas developed a new theory of culture known as historical particularism. Historical particularism, which emphasized the uniqueness of all cultures, gave new direction to anthropology. 43._____________ .8Boas felt that the culture of any society must be understood as the result of a unique history and not as one of many cultures belonging to a broader evolutionary stage or type of culture. 44._______________.Historical particularism became a dominant approach to the study of culture in American anthropology, largely through the influence of many students of Boas. But a number of anthropologists in the early 1900s also rejected the particularist theory of culture in favor of diffusionism. Some attributed virtually every important cultural achievement to the inventions of a few, especially gifted peoples that, according to diffusionists, then spread to other cultures. 45.________________.Also in the early 1900s, French sociologist Émile Durkheim developed a theory of culture that would greatly influence anthropology. Durkheim proposed that religious beliefs functioned to reinforce social solidarity. An interest in the relationship between the function of society and culture—known as functionalism—became a major theme in European, and especially British, anthropology.[A] Other anthropologists believed that cultural innovations, such as inventions, had a single origin and passed from society to society. This theory was known as diffusionism.[B] In order to study particular cultures as completely as possible, Boas became skilled in linguistics, the study of languages, and in physical anthropology, the study of human biology and anatomy.[C] He argued that human evolution was characterized by a struggle he called the ―survival of the fittest,‖ in which weaker races and societies must eventu ally be replaced by stronger, more advanced races and societies.[D] They also focused on important rituals that appeared to preserve a people‘s social structure, such as initiation ceremonies that formally signify children‘s entrance into adulthood.[E] Thus, in his view, diverse aspects of culture, such as the structure of families, forms of marriage, categories of kinship, ownership of property, forms of government, technology, and systems of food production, all changed as societies evolved.[F]Supporters of the theory viewed as a collection of integrated parts that work together to keep a society functioning.[G] For example, British anthropologists Grafton Elliot Smith and W. J. Perry incorrectly suggested, on the basis of inadequate information, that farming, pottery9making, and metallurgy all originated in ancient Egypt and diffused throughout the world. In fact, all of these cultural developments occurred separately at different times in many parts of the world.Part CDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written carefully on ANSWER SHEET 2. (10 points)There is a marked difference between the education which every one gets from living with others, and the deliberate educating of the young. In the former case the education is incidental; it is natural and important, but it is not the express reason of the association.46It may be said that the measure of the worth of any social institution is its effect in enlarging and improving experience; but this effect is not a part of its original motive. Religious associations began, for example, in the desire to secure the favor of overruling powers and to ward off evil influences; family life in the desire to gratify appetites and secure family perpetuity; systematic labor, for the most part, because of enslavement to others, etc. 47Only gradually was the by-product of the institution noted, and only more gradually still was this effect considered as a directive factor in the conduct of the institution. Even today, in our industrial life, apart from certain values of industriousness and thrift, the intellectual and emotional reaction of the forms of human association under which the world's work is carried on receives little attention as compared with physical output.But in dealing with the young, the fact of association itself as an immediate human fact, gains in importance.48 While it is easy to ignore in our contact with them the effect of our acts upon their disposition, it is not so easy as in dealing with adults. The need of training is too evident; the pressure to accomplish a change in their attitude and habits is too urgent to leave these consequences wholly out of account. 49Since our chief business with them is to enable them to share in a common life we cannot help considering whether or no we are forming the powers which will secure this ability.If humanity has made some headway in realizing that the ultimate value of every institution is its distinctively human effect we may well believe that this lesson has been learned largely through dealings with the young.50 We are thus led to distinguish, within the broad educational process which we have been so far considering, a more formal kind of education -- that of direct tuition or schooling. In undeveloped social groups, we find very little formal teaching and training. These groups mainly rely for instilling needed dispositions into the young upon the same sort of association which keeps the adults loyal to their group.Section & Writing10Part A51. Directions:Restrictions on the use of plastic bags have not been so successful in some regions. ―White pollution ‖is still going on. Write a letter to the editor(s) of your local newspaper to1)give your opinions briefly and2)make two or three suggestionsYou should write about 100 words. Do not sign your own name at the end of the letter. Use "Li Ming" instead. You do not need to write the address.Part B52. Directions:In your essay, you should1) describe the drawing briefly,2) explain its intended meaning, and then3) give your comments.You should write neatly on ANSHWER SHEET 2. (20 points)11。
2009年全国硕士研究生入学统一考试数学一真题及答案
当 时,
当 时,
因此函数 仅在 处间断,故选(B).
二、填空题:9-14小题,每小题4分,共24分,请将答案写在答题纸指定位置上.
(9)设函数 具有二阶连续偏导数, ,则 .
【答案】
【考点】多元函数的偏导数
【难易度】★★
【详解】本题涉及到的主要知识点:
利用复合函数的链式求导法则求多元函数的偏导数的方法。
在本题中,
,
(10)若二阶常系数线性齐次微分方程 的通解为 ,则非齐次方程 满足条件 的解为 .
【答案】
【考点】简单的二阶常系数非齐次线性微分方程
【难易度】★★
【详解】本题涉及到的主要知识点:
线性微分方程的解的性质即叠加原理,线性微分方程通解的结构为齐次方程的通解加上特解。
在本题中,
由通解表达式 该二阶线性常系数齐次方程的特征值为 ,于是特征方程为
,
而在 上, 有连续的一阶偏导数且 ,于是
(在 : 上用高斯公式)
(20)(本题满分11分)
设 , .
(Ⅰ)求满足 的 . 的所有向量 , .
(Ⅱ)对(Ⅰ)中的任意向量 , 证明 , , 线性无关.
【考点】向量组的线性无关,非齐次线性方程组的通解
【难易度】★★★
【详解】本题涉及到的主要知识点:
非齐次线性微分方程的解的性质即叠加原理,非齐次线性微分方程通解的结构为齐次方程的通解加上特解。
收敛级数的和的概念, 称为无穷级数 的前n项的部分和。若部分和数列 的极限存在,即 ,则称级数 收敛。当级数收敛时,其和 。
在本题中,
(Ⅰ)先求 .易求得 与 的交点为 , ,于是曲线 与 所围成区域的面积为
(Ⅱ)按定义求
(Ⅲ)求 .
华农考研参考书目
华中农业大学2009年硕士研究生考试参考书目参考书目-初试科目501园林设计《城市园林绿地规划》同济大学主编,中国建筑工业出版社。
《园林设计》唐学山主编,中国林业出版社,1997。
360数学《大学数学》(第2版) 谢季坚、李启文主编,高等教育出版社(面向21世纪课程教材或普通高等教育“十五”国家级规划教材)。
《线性代数及其应用》邓泽清主编,高等教育出版社(面向21世纪课程教材)。
《概率论及试验统计》余家林主编,高等教育出版社(面向21世纪课程教材或普通高等教育“十五”国家级规划教材)。
609化学《无机及分析化学》董元彦主编,科学出版社(面向21世纪课程教材)。
《有机化学》陈长水主编,科学出版社。
《有机化学》(第3版)汪小兰编,北京:高等教育出版社。
612社会统计学《社会统计学》卢淑华,北京大学出版社,2004年第4次印刷。
《社会研究的统计应用》李沛良,社会科学文献出版,2001年。
613教育学(含教育史)《教育学》王道俊、王汉澜主编,人民教育出版社,2008年2月。
《中国教育史》孙培青著,华东师范大学出版社,2007年1月。
614微生物学《微生物学》沈萍主编,高等教育出版社,2002。
616细胞生物学《细胞生物学》翟中和主编,高等教育出版社。
617社会学研究方法《现代社会调查方法》(第二版)风笑天著,华中科技大学出版社,2001年。
《社会学研究方法》(第二版)风笑天主编,中国人民大学出版社,2005年。
619法学综合(含法理学、宪法学、民法学、行政法学)《法理学》张文显主编,北京大学出版社,高等教育出版社(面向21世纪课程教材)。
《宪法学》周叶中主编,北京大学出版社,高等教育出版社(面向21世纪课程教材)。
《民法学》魏振瀛主编,北京大学出版社,高等教育出版社(面向21世纪课程教材)。
《法学概论》李长健主编,吉林人民出版社。
621公共管理学《公共管理学》张成福、党秀云著,中国人民大学出版社,2001年版。
2009年全国硕士研究生入学统一考试农学门类联考数学真题及详解【圣才出品】
3.函数 f (x) xx2 et2 dt 的极值点为 x=( 0
).
A. 1 2
B. 1 4
C.- 1 4
D.- 1 2
【答案】A
【解析】因 f (x) e xx2 2 (x x2 ) (1 2x)exx2 2
令 f (x) 0 ,得 x 1 ,又 2
f (x) 2exx2 2 (1 2x) e xx2 2
圣才电子书
十万种考研考证电子书、题库视频学习平
台
2009 年全国硕士研究生入学统一考试农学门类联考数学真题及详解
一、选择题:1~8 小题,每小题 4 分,共 32 分.下列每题给出的四个选项中,只有
一个选项是符合题目要求的,请将所选项前的字母填在括号内. 1.在(-π,π)内,函数 y x 的可去间断点的个数为( ). tan x A.0
圣才电子书
【答案】 4 3
【解析】由于
十万种考研考证电子书、题库视频学习平 台
,所以
原式
12.设 f(u,v)为二元可微函数, Z
f (sin(x
y),e
xy
)
,则
z x
____.
【答案】 fu cos(x y) yfvexy
【解析】函数 z z(x, y) 由 z f (u, v),u sin(x y), v exy 复合而成,根据复合函
A 项, P AB P( A U B) 1 P( A U B) ,因为 P( A U B) 不一定等于 1,所以
P( AB) 不一定等于 0. B 项,只有当 P(A),P(B)为 0 或事件 A,B 相互独立时才成立. C 项,只有当 A,B 互为对立事件的时候才成立.
D 项, P( A U B) P AB 1 P( AB) 1.
2009年考研数学一、二、三真题(含详解)
O
A
O
A O
A
1
O B1
B
O
B
O
B
O
6
A1
O
O
6
1 A
A
1 B
B
6
O
O
1 2
A
1 B 3 O
O 3A
6
6
(D) a 1,b 1 6
【解析】 f x x sin ax 与 g x x2 ln 1 bx 是 x 0 时的等价无穷小,则
lim
x0
f (x) g(x)
lim
x0
x sin ax x2 ln(1 bx)
lim
x0
x sin ax x2 (bx)
lim
x0
x
sin ax bx3
,且单调递减;
0
(定积分对应的图像位于 x 轴下方)
③ x 1, 2 时, F(x) x f (t)dt 0 单调递增; 0
④ x 2,3 时, F '(x) f (x) 0 为常函数;
⑤ F (x) 为连续函数. 结合这些特点,可见正确选项为(D)
(4)
设有两个数列
an
,
bn
,若
lim
n
则 max 1k 4
Ik
(
)
D1
D2
D4
-1
D3
1
x
(A) I1
(B) I2 (C) I3 (D) I4
-1
【答案】(A)
【解析】本题利用二重积分区域的对称性及被积函数的奇偶性.令 f (x, y) y cos x ,
D2, D4 两区域关于 x 轴对称, f (x, y) y cos x f (x, y) ,即被积函数是关于 y 的奇函数, 所以 I2 I4 0 ;
江西农业大学研究生入学考试数学2009年
第 1 页 共4 页1江 西 农 业 大 学2009年招收攻读硕士学位研究生入学考试试题适用学科、专业 理 科 考 试 科 目 360 数 学 注意事项:所有答案一律在答题纸上填写,否则无效。
一、填空题(共6小题,每小题4分,共24分)1. 设)(x f y =的定义域为[]2,1,则)ln 1(x f -的定义域是 .2. 若⎪⎩⎪⎨⎧=≠-+=.0,,0,12sin )(2x a x x e x x f ax 在(-),+∞∞上连续,则=a .3. 设是的一个原函数,则 .2x e -)(x f ()f x '=4. 设矩阵为四阶方阵, 则分块矩阵的秩为 .A ()E A ,5.设为三阶正交矩阵, 且,,则的解为 . ()ij A a =133-=a ⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡=100b b Ax =6. 甲乙两人向同一目标独立地各射击一次,命中率分别为、,3121现已知目标被击中,则它是由甲命中的概率为 .二、单项选择题(共8小题,每小题4分,共32分)1. 下列式子正确的是( ).(A) , (B) , 1lim 11x x x e e →∞+=-1lim 11x x x e e →-∞+=-(C) , (D) .
01lim sin 1x x x →=2lim 11x
x x x →∞+⎛⎫= ⎪+⎝⎭准考证号:
姓名:
装
订
线。
2009年考研数一真题及答案
2009年全国硕士研究生入学统一考试数学一试题答案解析一、选择题:1~8小题,每小题4分,共32分,下列每小题给出的四个选项中,只有一项符合题目要求,把所选项前的字母填在题后的括号内.(1)当0x →时,()sin f x x ax =-与()()2ln 1g x x bx =-等价无穷小,则()A 11,6a b ==-. ()B 11,6a b ==. ()C 11,6a b =-=-. ()D 11,6a b =-=. 【答案】 A【解析】2()sin ,()ln(1)f x x ax g x x bx =-=-为等价无穷小,则222200000()sin sin 1cos sin lim lim lim lim lim ()ln(1)()36x x x x x f x x ax x ax a ax a ax g x x bx x bx bx bx →→→→→---==-⋅---洛洛230sin lim 166x a ax a b b axa→==-=-⋅ 36a b ∴=- 故排除,B C 。
另外201cos lim 3x a axbx→--存在,蕴含了1cos 0a ax -→()0x →故 1.a =排D 。
所以本题选A 。
(2)如图,正方形(){},1,1x y x y ≤≤四个区域()1,2,3,4k D k =,cos kk D I y xdxdy =⎰⎰,则{}14max k k I ≤≤=()A 1I .()B 2I . ()C 3I .()D 4I .【答案】A【解析】本题利用二重积分区域的对称性及被积函数的奇偶性。
24,D D 两区域关于x 轴对称,而(,)cos (,)f x y y x f x y -=-=-,即被积函数是关于y 的奇函数,所以240I I ==;13,D D 两区域关于y 轴对称,而(,)cos()cos (,)f x y y x y x f x y -=-==,即被积函x数是关于x 的偶函数,所以{}1(,),012cos 0x y y x x I y xdxdy ≥≤≤=>⎰⎰;{}3(,),012cos 0x y y x x I y xdxdy ≤-≤≤=<⎰⎰.所以正确答案为A.(3)设函数()y f x =在区间[]1,3-上的图形为:则函数()()0xF x f t dt =⎰的图形为()A ()B()C ()D【答案】D【解析】此题为定积分的应用知识考核,由()y f x =的图形可见,其图像与x 轴及y 轴、0x x =所围的图形的代数面积为所求函数()F x ,从而可得出几个方面的特征:①[]0,1x ∈时,()0F x ≤,且单调递减。
华中农业大学硕士研究生入学考试
华中农业大学硕士研究生入学考试数学分析(628 )大纲试卷满分及考试时间试卷满分为150分,考试时间为180分钟.答题方式答题方式为闭卷、笔试.试卷题型结构单选题与填空题约50分解答题(包括证明题)约100分第一部分:实数集与函数,极限,连续考试内容:1.实数集的性质,实数集的上(下)确界。
2.实数完备性的基本定理。
3.函数的定义,函数的各种表示方法,基本初等函数的定义、性质及图像,复合函数、反函数、有界函数、周期函数、奇函数和偶函数、单调函数、初等函数的定义。
4.数列和函数极限的定义,数列和函数极限的性质。
5.数列的单调有界定理,数列和函数收敛的柯西收敛准则,归结原则。
6.两个重要极限及其应用。
7.无穷小量与无穷大量的概念及其阶的比较。
8.函数连续的概念,函数的间断点及其分类,复合函数与反函数的连续性。
9.闭区间上连续函数的性质。
10.函数的一致连续性的概念及相关结论。
考试要求:1.掌握实数集的有序性与稠密性,掌握实数集的上(下)确界的定义,会确定一些常见集合的上(下)确界。
2. 掌握实数完备性六个基本定理:确界原理、单调有界定理、区间套定理、有限覆盖定理、聚点定理和柯西收敛准则。
3. 掌握函数的定义,函数的各种表示方法;掌握基本初等函数的定义、性质及图像,掌握复合函数、反函数、有界函数、周期函数、奇函数和偶函数、单调函数、初等函数的定义。
4. 掌握数列极限的N -ε定义和函数极限的δε-定义,掌握数列和函数极限的唯一性、有界性、保号性、迫敛性、不等式性质以及四则运算性质,并会利用这些性质证明相关结论,求某些数列和函数的极限。
5. 掌握数列的单调有界定理,掌握数列和函数收敛的柯西收敛准则,掌握归结原则,并利用这些定理证明相关结论。
6. 掌握两个重要极限1sin lim 0=→x x x 与e x xx =+∞→)11(lim ,并应用这两个重要极限求其它相关数列或函数的极限。
7. 掌握无穷小量的概念,掌握无穷小量阶的比较,会应用无穷小量阶的比较证明相关结论,求相关极限;掌握大量的概念,掌握无穷大量与无穷小量之间的关系;会确定曲线的渐近线。