G2-常用符号和数学表达式.doc

Chapter2 专业英语中常用符号和数学表达式1数的分类complex number 复数zero; naught;0 零real number 实数imaginary number 虚数relational number 有理数irrational number 无理数integer number 整数positive integer number 正整数natural number 自然数negative integer number 负整数fraction 分数decimal 小数odd number 奇数even number 偶数cardinal number 基数ordinal number 序数approximate number 近似数significant number 有效数2整数addition 加法subtraction 减法addend 加数subtrahend 减数augend 被加数minuend 被减数plus sign 加号minus sign 减号sum 和difference（diffa）差plus; add; and; increase 加minus; subtract; decrease 减is; equal 等division 除法multiplication 乘法divide 除multiply; multiplied by; times 乘divisor 除数multiplier 乘数dividend 被除数multiplicand 被乘数quotient 商product 积remainder 余数positive 正negative 负3小数和分数numerator 分子denominator 分母decimal point 小数点naught point four 零点四fraction stroke 分数线recurring decimal 循环小数4百分数percent 百分比permill 千分比average 平均数round off 舍入discount 折扣interest 利息5幂与指数power 幂; 乘方root-extracting 开方exponent 指数logarithms 对数X squared 某数的平方cube 三次方three cubed 三次方的four 乘四次方cube root 立方根square root 平方根to rise to the power of five 使乘五次方radical sign根号6代数algebra 代数equation 等式; 方程式inequality 不等式unknown number 未知数absolute value绝对值simple equation 一次方程quadratic equation 二次方程cubic equation 三次方程monomial 单项式polynomial 多项式variable 变量coefficient 系数differential 微分integral 积分derivative 导数function 函数ratio 比proportion 比例sign of equality等号sign of inequality不等号interval 区间matrix 矩阵theorem 定理lemma 引理definition 定义7常用数学表达式数值1/2a half; one halfl/3a third; one third2/3two thirds1/4a quarter; one quarter; a fourth; one fourthl/100a(one) hundredthl/1,000a(one) thousandth113/324one hundred and thirteen over three hundred and twenty-fourfour and two-thirdsforty-five and eighty-nine over twenty-three0.1one tenth; point one0.01one hundredth; point zero one0.001one thousandth; point zero zero one; point two zero one2050.0357two thousand and fifty point zero three five seven0.25zero point two fivepoint two five repetend fivezero point two five recurringzero point three seven twenty-five recurring对483579四舍五入到千位round off 483579 to nearest thousand108one followed by eighteen zeros-30.8negative thirty point eight2-3itwo minus three i; two minus three times i2two per cent; two percent5five per mill; five permillinfinity实数xyzx plus y is z; add x to y is z; x and y is z(xy)bracket x plus y bracket closedx-yx minus y; subtract y from x; y from x; x subtracts yxyx plus or minus yxy; xyxy; multiply x by y; x multiplied by y; x by y; x times y;xydivide x by y; y into x x over yx : ythe ration of x to yxyx varies as y; x is in direct proportion to yxyx equals y; x is equal to y; x is yxyx is not equal to y; x is not yxyx is identical to y; x is equivalent to y; x is equivalent to y;xyx is approximately equal to y; x approximately equals yxyx is greater than y; x is more than yxyx is much greater than y; x is far greater than yxyx is greater than or equal to yxyx is less than yxyx is much less than yxyx is less than or equal to y0x1zero is less than x is less than 1; x is greater than zero and less than 10x1zero is less than or equal to x is less than or equal to 1x2x square; x squared; the square of x; the second power of x; x to second powerx3x cube; x cubed; the cube of x; the third power of x; x to the third powerxnthe nth power of x; x to the nth power; x to the power nthe square root of x; x squaredthe cube root of xthe nth root of xx-nx to the (power) minus n(x+y)2x plus y all squaredx over y all squaredx ix i; x sub i;x subscript i; x suffix i函数lognxlog x to the base n; log of x to the base nlog10xlog x to base 10; common logarithmlogex; lnxlog x to the base e; log to the base e of y; natural log (of) y ex; exp(x)exponential function of x, e to the power xthe summation of x sub i, where i goes from 1 to n;the sum from i equals one to n x i;the sum as i runs from one to n of the x ithe product of x sub i, where i goes from one to nthe product of all x i from i equals one to nthe product of all xi from i equals one to infinitythe absolute value of x; mod x; modulus xthe mean value of x; x barx hatx tildex*x asteriskx primex double primex double prime sub mf(x)f x; f of x; the function f of x a function f from S to Tf(x)f prime x; f dash x; the (1st) derivative of f with respect to x f(x)f doubleprime x; f doubledash x; the second derivative of f with respect to x f(x)f tripleprime x; f tripledash x; the third derivative of f with respect to xf4(x)four x; the fourth derivative of f with respect to xx!x factorialfinite difference or incrementx,xthe increment of xdxd x; d of x; differential xdel; nablanth del (nabla)d y over d x;the differential coefficient of y with respect to x; the first derivative of y with respect of xthe second derivative of y with respect of xthe nth derivative of y with respect of xthe partial (derivative) of y with respect to uthe second partial (derivative) of y with respect to x the partial derivation of z with respect to x of the partial derivative of z with respect to y integral ofdouble Integral ofn-fold integral ofthe integral between limits a and b; the integral from a to bthe indefinite integral of a times x with respect to xthe integral from a to b of function of xthe double integral of f of x,ythe limit as x approaches 0the limit as x approaches 0 from abovethe limit as x approaches 0 from below逻辑there existsfor allbecausethereforexythe difference between x and yxyx implies y; if x, then yxyx if and only if y; x is equivalent to y; x and y are equivalent集合 ; empty setxAx belongs to A; x is an element (or a member) of AxAx does not belong to A; x is not an element (or a member) of AABA is contained in B; A is a subset of BABA contains B;B is a subset of AABA cap B; A meet B; A intersection BABA cup B; A join B; A union BABA minus B; the difference between A and BABA cross B; the Cartesian product of A and B(A与B的笛卡尔积)线性代数|A|the norm (or modulus) of Avector FAB; the length of the segment ABATA transpose; the transpose of AA-1A inverse; the inverse of A xyx maps into y; x is sent (or mapped) to yxx approaches infinity几何xangle xx is perpendicular to yx is parallel to ysinsinecoscosinetg, tantangentctg, cotcotangentsc, secsecantcsc, coseccosecantsin-1, arcsinarc sinecos-1, arcosarc cosinesinhthe hyperbolic sinecoshthe hyperbolic cosine( )round brackets; parentheses ;the signs of grouping square（angular）brackets; bracketangle bracketbraces8基底（进制）radix进制；基数quarnary四进制binary二进制quinary五进制octal八进制senary六进制decimal十进制duodecimal十二进制hexsedecimal十六进制 9常用希腊字母字母读音字母读音字母读音alphabeta,gamaxi,psideltaepsilonzeta,phiomegalambdamnnuetarho,sigmataupi10其他数学名词line 线angle 角intersecting line 相交线parallel line 平行线triangle 三角形quadrilateral 四边形rectangle 矩形lozenge 菱形square正方形polygon多边形circle圆arc弧perimeter周长area面积diameter直径volume体积11具体读法实例y=f(x)y is a function of x6530six times (multiplied by) five equals (is equal to) thirty(x-y)(x+y)x minus y; x plus ythe fifth root of x squarey-10y to the minus tenth (power)20 : 516 : 4the ratio of 20 to 5 equals the ration of 16 to 4 (20 is to 5 as 16 is to 4)e=1.610-19e equals one point multiplied by ten to minus nineteenth power10-nten to the minus none over n squareone over one minus n times z reversef(x)=ax2+bx+cthe func