数学符号念读

Mathematics Symbols and Their English Explanations1/2 a half or one half1/3 a third or one third2/3 two third1/4 a quarter or one quarter; a fourth or one fourth1/10 a tenth or one tenth1/100a [one] hundredth 1/1000a [one] thousandth 1/1234one over a thousand two hundred and thirty-four 3/4three fourths or three quarters 4/5three fifths or four over five 113/300one hundred and thirteen over three hundred 212two and a half 872two and seven over eight or two and seven eighths 813three and one eighth 314four and a third 43125a [one] hundred twenty-five and three fourths [quarters] 0.1(or .1)0 point one or zero point one or nought point one 0.01(or .01)0 point 0 one or zero point zero one or nougth point nought one 0.25(or .25)nougth point two five or point two five 0.045decimal [point] nought four five 2.35two point three five 4.9four point nine recurring 3.0362three point nought three two six , two six recurring 45.67four five [forth-five] point six seven 38.72three eight point seven two or thirty-eight decimal seven two0.001(or .001) 0 point 0 0 one nought point nought nought one or zero pointzero zero one or point nought nought one+ plus; positive_ minus; negative±plus or minus⨯(or.) multiplied by ; times÷(or/) divided by= is equal to ; equals≡is identically equal to≈(or≅;Ω;=) is approximately equal to ; approximately equals≡identical with= or ≠not equal to→or= approaches< less thangreater than<< much less than>> much greater than≤equal to or less than≥equal to or greater than( ) round brackets; parentheses[ ] square brackets[ ] angular brackets{ } braces⋂intersection⋃union∈is member of set⊂is a subset of~ similar to ; difference* denotes an operation⇔is equivalent to⇒implies{ }or∅empty set→maps into∴thereforebecause: ratio sign, divided by, is to:: equals, as (proportion)∝varies as∞infinitysquare root of3cube root of║ parallel to。

degrees, minutes” seconds∠angleAB length of line from A to BA⨯B vector product of A and B; magnitude of A times magnitudeof B times sine of the angle from A to B; AB sin ABA B∙scalar product of A to B ; magnitude of A times magnitudeof B times cosine of the angle form A to B ;AB cos ABI or j imaginary or square root of -1ωor 2ωthe imaginary cube roots of 1πpi ; the ratio of the circumference of a circle to its diameter,approx.3.14159e or ε①the base of natural logarithms, approx.2.71828② the eccentricity of a conic sectionx ! or x factorial xn log x log x to the base n10log x or lg x log x to the base 10 (common logarithm)e log x or ln x log x to the base (natural logarithm or Naperian logarithm ) Mmodulus of common logarithms 10log e = 0.4343, (10log x = e log x ⨯0.4343) 1-Me l o g 10 = 2.3026, (e log x = 10log x ⨯ 2.3026) n xx x.x …to n factors, the nth power of x, x to the power n n x or n x 1the nth root of x,x to the power one over n th X → ax approaches the limit a θ(the angle between the radius vector and the polar axis) the angle theta ∑sigma ∏the product of the terms indicated xthe absolute value of x xthe mean value of x ; x bar b 'b prime b ''b double prime ; b second prime b '''b triple prime 1bb sub one 2bb sub two m bb sub m xx dot ,first derivative of x with respect to time x x two dot , second derivative of x with respect to timeexp x = x e (e = naperian log base )(abbreviation for x e ) n m b b double prime sub mf or F functionf(x );F(x );∅(x )… function f(or ∅) of xy = f(x) y is a function of x∆ ( finite difference or increment) deltax ∆or σx(the increment of x ) delta x x d(an increment of x considered as tending to zero )dee of x ; dee x ; differential of x yxd d or xy Dthe differential coefficient of y with respect to xthe first derivative of y with respect to x 2y d /2x dthe second derivative of y with respect x ; n y d /nx dthe nth derivative of y with respect x y ∂/u ∂the partial derivative of y with respect u ,uwhere y is a function of u and another variable (or variables) F '(x)the first derivative of function F of x with respect to x ∇i ∂/x ∂+j ∂/y ∂+k ∂/z ∂ del ; nabla; vector differential operator ∇nnth del (nabla) ιLaplacian operator 4!Factorial =1432⨯⨯⨯ ⎰line integral around a closed path ⎰integral ⎰ab integral between limits a and bF vector Fx+y x plus y(a+b) bracket a plus b bracket closeda =b a equal b ; a is equal to b ; a is ba ≠b a is not equal b ; a is not ba±b a plus or minus ba≈b a is approximately equal to ba>b a is greater than ba>>b a is much [far] greater than ba≥b a is greater than or equal to ba b a is not greater than ba<b a is less than ba<<b a is much less than ba b≤a is less than or equal to ba ba is not less than ba b⊥a is perpendicular to bx=∞x approaches infinitya b≡ a is identically equal to b ; a is of identity∠angle aaa‖b a is parallel to ba∽b the difference between a and ba b∝a varies directly as b11⨯=1 one one is one22⨯=4 twice two is four65⨯=30 six times [multiplied by] five equals [is equal to; are;makes ; make] thirty30=65⨯thirty is five times as large as sixs=vt s equals [is equal to] v multiplied by t;s equals v times t 1:2 the ratio of one to two123÷=4 12 divided by 3 equals [is] 420:5=16:4 the ratio of 20 to 5 equals the ratio of 16 to 4 ; 20 is to 5as 16 is to 4a:b :: c:d a is to b as c is to da+b=c a plus b is [are; equals; is equal to] cc-b=a c minus b is [equals; is equal to] a ; b from c leaves a v=t sv equals s divided by t ; c is s over t 7+3<127 plus 3 is less than 12 12>7+312 is greater than 7 plus 3 72-16=5672 minus 16 is [equals; is equal to] 56; 16 from 72 leaves 56 2xx square ; x squared; the square of x ; the second power of x ; x to the second power 25=25the second power of 5 is 25 ; 5 square is 25 ; 5 to the second power is equal to 25 3yy cube ; y cubed ;the cube of y ; y to the third power ; y to the third 10-yy to the minus tenth(power) 4=2±the square root of 4 is [equals] plus or minus 2 3athe cube root of a 52xthe fifth root of x square 518the square root of five hundred and eighteen 3930the cube root of nine hundred and thirty 3x=5three times x equals 5 3x /5=2y x to the third power divided by five equals ysquared2x +2y =10 x squared with y squared equals 10 a=tV V t - a equals v sub t minus v over [divided by] t (a+b-c f e d =÷⨯) a plus b minus c multiplied by d , all divided by e equals f (8+6212)468.385÷⨯-eight plus six and five-eighths minus three decimal [point] six eight multiplied by four, all divided by two and a half 456719823=÷余1323 into 4567 goes 198 times, and 13 remainder 45+70+152=26745,70 and 152 added together are 267 %per cent 2%two per cent 000per mille 5000five per mille 83%three eighths (of one)per cent 0.3%point three per cent 21tonhalf ton 32tontow third of a ton 43kmthree quarters of a kilometer 1.75kmone point seven five kilometer 60hr misixty miles per hour 20C 0twenty degrees 6'① 6 minutes ② 6 feet 01''① 10 seconds ② 10 inches 0C 0 zero degree Centigrade [Celsius]100C 0 one [a] hundred degrees centigrade32F 0 thirty-two degrees FahrenheitSet theory, relations, functionsX , Y Setx X ∈ x is a member of the set Xx X ∉ x is not a member of XA X A X ⊆⊂, Set A is contained in set XX A X A ⊆⊄, A is not contained in XY X Y X +⋃, Union of sets X and YY X Y X .,⋂ Intersection of sets X and Y+,+,O Symmetric difference of sets∑⋃xi Xi , Union of all the sets Xxi Xi ∏⋂, Intersection of all the sets X,0,φ∧ Null set , empty setCX CX X ,,' Complement of the set XX-Y , X\Y Difference of sets X and Y)}(:{)},({)),((^x P x x P x x p x The set of all x with the property p(x , y , z), ( x, y, z) Ordered set of elements x , y, and z; to bedistinguished from (x, y, z), for example( x, y, z) Unordered set, the set whose elements are x, y,z, and no others{ ,...,,21a a },{i a } i=1,2...,n 1}{=i n i aThe set whose members are i a , where i isany whole number from 1 to n{ ,...,21a a },{i a } i=1,2...,∞=1}{i i aThe set whose members are i a , where i is anypositive whole numberY X ⨯ Cartesian product, set of all (x , y) such thatY y X x ∈∈,I i a i ∈}{ The set whose elements are a , where I i ∈ Xry ,R {x , y} Relation,,≅≡∽,≈ Equivalence relations, for example, congrucnce ≥,≧,>,>>,≦,≤,< Transitive relations, for example, numerical orderf : X f Y f Y X y X Y X ∈→−→−→,,, Function, mapping, transformationY X f f f −→−---111,, Inverse mapping g 。