G2-常用符号和数学表达式

1、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

2、number 序数approximate number 近似数significant number 有效数2.整数addition 加法subtract ion 减法addend加数subtrahe nd 减数auge nd被加数minuend被减数plus sign 力口号minus sign 减号sum和differenee diffa差plus; add; and; in crease 力口minus; subtract; decrease 减is; equal 等division 除法multiplicati on 乘法divide 除multiply; multiplied by;

3、times 乘divisor 除数multiplier 乘数divide nd被除数multiplica nd 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.幕与指数po

4、wer幂;乘方root-extracting 开方exponent 指数logarithms 对数X squared某数的平方cube二次方three cubed 二次方的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in equality 不等式unknown number 未知数absolute value 绝对值simple equati on 次方程quadratic equation 一次方程cubic eq

5、uation 二次方程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sig n of in equality 不等号interval 区间matrix矩阵theorem 定理lemma引理definition 定义1/2a half; one halfl/3a third; one third2/3two thirds1/4a quarter; one quart

6、er; a fourth; one fourth1/100a(one) hun dredth1/1,000a(one) thousa ndth113/324one hundred and thirteen over three hundred and twen ty-four423four and two-thirds2345 89forty-five and eighty-nine over twen ty-three0.1one ten th; point one0.01one hun dredth; point zero one0.001one thousa ndth; point ze

7、ro zero one; point two zero one2050.0357two thousand and fifty point zero three five seven0.25zero point two five0.25point two five repetend five0.25zero point two five recurring0.3725zero point three seve n twen ty-five recurri ng对 483579 四舍五入到千位round off 483579 to nearest thousand108one followed b

8、y eightee n zeros-30.8n egative thirty point eight2-3itwo minus three i; two minus three times i7 常用数学表达式数值2 %two per cent; two perce nt5 %。five per mill; five permillOOinfinityx + y= zx plus y is 乙 add x to y is 乙 x and y is z(x + y)bracket x plus y bracket closedx-yx mi nus y; subtract y from x; y

9、 from x; x subtracts yx ± yx plus or minus yx X y； xyxy; multiply x by y; x multiplied by y; x by y; x times y;x十ydivide x by y; y into xxyx over yx : ythe ratio n of x to yx * yx varies as y; x is in direct proporti on to yx = yx equals y; x is equal to y; x is yx丰yx is not equal to y; x is no

10、t yx = yx is ide ntical to y; x is equivale nt to y; x is equivale nt to y;xyx is approximately equal to y; x approximately equals yx > yx is greater tha n y; x is more tha n yx»yx is much greater than y; x is far greater than yx > yx is greater tha n or equal to yx v yx is less tha n yx&

11、lt;<yx is much less tha n yx < yx is less tha n or equal to y0 v x v 1zero is less tha n x is less tha n 1;x is greater tha n zero and less tha n 10 W x W 1zero is less tha n or equal to x is less tha n or equal to 1x2x square; x squared; the square of x;the sec ond power of x; x to sec ond po

12、werx3x cube; x cubed; the cube of x; the third power of x; x to实数the third powerxnthe nth power of x; x to the nth power; x to the power nJxthe square root of x; x squaredVxthe cube root of xv'xthe nth root of xx-nx to the (power) mi nus n(x+y)2x plus y all squared(Fyx over y all squaredx ix i;

13、x sub i;x subscript i; x suffix ilognxlog x to the base n; log of x to the base nlogioxlog x to base 10; com mon logarithmlog ex; Inxlog x to the base e; log to the base e of y; n atural log (of) yex; exp(x)exponential function of x, e to the power xnXii 1the summation of x sub i, where i goes from

14、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 inXii 1the product of x sub i, where i goes from one to nthe product of all x i from i equals one to nXii 1the product of all xi from i equals one to infin ityx|the absolute value of x; mod x; modulus xxthe mean value

15、 of x; x barAxx hatxx tilde*xx asterisk1xx primeIIxx double primexmx double prime sub mf(x)f x; f of x; the function f of x函数f :S Ta fun ctio n f from S to Tf (x)f prime x; f dash x; the (1st) derivative of f with respect toxf (x)f double -prime x; f double ash x; the second derivative of f with res

16、pect to xf (x)f triple -prime x; f triple ash x; the third derivative of f with respect to xf4(x)four x; the fourth derivative of f with respect to xx!x factorialfin ite differe nee or in creme nt x, S xthe in creme nt of xdxd x; d of x; differe ntial xdel; n ablannth del (nabla)dy dxd y over d x;th

17、e differential coefficient of y with respect to x;the first derivative of y with respect of xd2y 页the sec ond derivative of y with respect of xdny dnxthe nth derivative of y with respect of x_yxthe partial (derivative) of y with respect to u2y2xthe sec ond partial (derivative) of y with respect to x

18、2zx ythe partial derivation of z with respect to x of the partial derivative of z with respect to y/in tegral offfdouble In tegral of卜fn-fold in tegral ofbathe in tegral betwee n limits a and b; the in tegral from a to baxdxthe indefinite integral of a times x with respect to xf (x)dxathe in tegral

19、from a to b of function of xf (x)dxdythe double in tegral of f of x,ylimx 0the limit as x approaches 0limx 0the limit as x approaches 0 from abovelimx 0the limit as x approaches 0 from belowthere existsfor allbecausethereforexythe differe nee betwee n x and yx yx implies y; if x, then yx yx if and o

20、nly if y; x is equivale nt to y; x and y are equivale nt ;empty setx Ax bel ongs to A; x is an eleme nt (or a member) of Ax Ax does not bel ong to A; x is not an eleme nt (or a member) of AA BA is contained in B; A is a subset of BA BA contains B;B is a subset of AA BA cap B; A meet B; A intersectio

21、n BA BA cup B; A join B; A un io n BABA minus B; the difference between A and BA X BA cross B; the Cartesian product of A and B(A 与 B 的笛卡 尔积)l|A|the norm (or modulus) of AFvector FABAB; the length of the segment ABAtA tran spose; the tran spose of A逻辑合线 性 代 数A-1A in verse; the in verse of Ax t yx ma

22、ps into y; x is sen t (or mapped) to yx fgx approaches infinity/ xan gle xx yx is perpe ndicular to yx/ yx is parallel to ysinsi necoscosinetg, tantangentctg, cotcota ngentsc, secseca ntcsc, coseccosecant-1sin , arcsinarc sine-icos , arcosarc cos inesi nhthe hyperbolic sinecoshthe hyperbolic cos ine

23、()round brackets; pare ntheses ;the sig ns of group ingsquare (angular) brackets; bracket< >an gle bracketbraces几何8.基底进制radix进制；基数quar nary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十八进制9 常用希腊字母字母、+ & 读曰字母、+ & 读曰字母、+ & 读曰alphabetagamaxi5psiJdeltaepsi

24、lo nzetaphiJomegaJlambdamnnuetarhosigmataupi10.其他数学名词line 线angle 角in tersect ing 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 fun ctio n of x6 X 5 = 30six times (multiplied by) fiv

25、e equals (is equal to) thirty(x-y)(x+y)x mi nus y; x plus y52vxthe fifth root of x squarey-10y to the minus tenth (power)20 : 5 = 16 : 4the ratio of 20 to 5 equals the ratio n of 16 to 4 (20 is to5 as 16 is to 4)e=1.6 X 10-19e equals one point multiplied by ten to minusnin etee nth power10-nten to the minus n1孑one over n square11 nz 1one over one minus n times z reverse2f(x)=ax +bx+cthe function of x equals a times the square of