常用数学符号英文对照.docx

1、常用数学符号英文对照常用数学符号英文对照Basic math symbolsSymbolSymbol NameMeaning / definitionExample=equals signequality5 = 2+35 is equal to 2+3not equal signinequality5 45 is not equal to 4approximately equalapproximationsin(0.01) 0.01,xymeansxis approximately equal toystrict inequalitygreater than5 45 is greater th

2、an 4strict inequalityless than4 54 is less than 5inequalitygreater than or equal to5 4,xymeansxis greater than or equal toyinequalityless than or equal to4 5,x ymeansxis greater than or equal toy( )parenthesescalculate expression inside first2 (3+5) = 16 bracketscalculate expression inside first(1+2

3、)(1+5) = 18+plus signaddition1 + 1 = 2minus signsubtraction2 1 = 1plus - minusboth plus and minus operations3 5 = 8 and -2minus - plusboth minus and plus operations3 5 = -2 and 8*asteriskmultiplication2 * 3 = 6times signmultiplication2 3 = 6multiplication dotmultiplication2 3 = 6division sign / obel

4、usdivision6 2 = 3/division slashdivision6 / 2 = 3horizontal linedivision / fractionmodmoduloremainder calculation7 mod 2 = 1.perioddecimal point, decimal separator2.56 = 2+56/100abpowerexponent23= 8abcaretexponent2 3= 8asquare rootaa= a9= 33acube root3a3a3a= a38= 24afourth root4a4a4a4a= a416= 2nan-t

5、h root (radical)forn=3,n8= 2%percent1% = 1/10010% 30 = 3per-mille1 = 1/1000 = 0.1%10 30 = 0.3ppmper-million1ppm = 1/100000010ppm 30 = 0.0003ppbper-billion1ppb = 1/100000000010ppb 30 = 310-7pptper-trillion1ppt = 10-1210ppt 30 = 310-10Geometry symbolsSymbolSymbol NameMeaning / definitionExampleanglefo

6、rmed by two raysABC = 30measured angleABC = 30spherical angleAOB = 30right angle= 90 = 90degree1 turn = 360 = 60degdegree1 turn = 360deg = 60degprimearcminute, 1 = 60 = 6059double primearcsecond, 1 = 60 = 605959lineinfinite lineABline segmentline from point A to point Brayline that start from point

7、Aarcarc from point A to point B= 60perpendicularperpendicular lines (90 angle)ACBC| |parallelparallel linesAB| |CDcongruent toequivalence of geometric shapes and sizeABC XYZsimilaritysame shapes, not same sizeABC XYZtriangletriangle shapeABC BCD|x-y|distancedistance between points x and y|x-y| = 5pi

8、 constant= 3.141592654.is the ratio between the circumference and diameter of a circlec=d= 2rradradiansradians angle unit360 = 2 radcradiansradians angle unit360 = 2cgradgradians / gonsgrads angle unit360 = 400 gradggradians / gonsgrads angle unit360 = 400gAlgebra symbolsSymbolSymbol NameMeaning / d

9、efinitionExamplexx variableunknown value to findwhen 2x= 4, thenx= 2equivalenceidentical toequal by definitionequal by definition:=equal by definitionequal by definitionapproximately equalweak approximation11 10approximately equalapproximationsin(0.01) 0.01proportional toproportional toyxwheny=kx, k

10、constantlemniscateinfinity symbolmuch less thanmuch less than1 1000000much greater thanmuch greater than1000000 1( )parenthesescalculate expression inside first2 * (3+5) = 16 bracketscalculate expression inside first(1+2)*(1+5) = 18 bracessetxfloor bracketsrounds number to lower integer4.3 = 4xceili

11、ng bracketsrounds number to upper integer4.3 = 5x!exclamation markfactorial4! = 1*2*3*4 = 24|x|single vertical barabsolute value| -5 | = 5f(x)function of xmaps values of x to f(x)f(x) = 3x+5(fg)function composition(fg) (x) =f(g(x)f(x)=3x,g(x)=x-1 (fg)(x)=3(x-1)(a,b)open interval(a,b) = x|axbx (2,6)a

12、,bclosed intervala,b = x|axbx 2,6deltachange / differencet=t1-t0discriminant =b2- 4acsigmasummation - sum of all values in range of seriesxi= x1+x2+.+xnsigmadouble summationcapital piproduct - product of all values in range of seriesxi=x1x2.xnee constant/ Eulers numbere= 2.718281828.e= lim (1+1/x)x,xEuler-Mascheroni constant = 0.527721566.golden ratiogolden ratio constantpi constant= 3.141592654.is the ratio between the circumference and diameter of a circlec=d= 2rLinear Algebra SymbolsSymbolSymbol NameMeaning / definitionExamp