0.25 zero(O, naught) point two five plus, positive plus or minus multiplied by, time divided by be equal be approximately equal to, approximately equals round brackets; parentheses square(angular) brackets braces equal to more than or equal to finity aps into xty bracket a plus b bracket closed a=b a equals b; a is equal to b; a is b a≠b a is not equal to b; a is not b a±b a plus or minus b a≈b a is approximately equal to b a>b a is greater than b a is much [far] greater than b a≥b a is greater than or equal to b a is less than b a<< b a is much less than b a≤b a is less than or equal to b a is perpendicular to b x→0 r approaches infinity ≡ a is identically equal to b; a is of identity to b angle ab a is parallel to b b the difference between a and b a∝b a varies directly as b r square; x squared; the square of x; the second power of x; x to second power x cube; x cubed; the cube of x; the third power of x; x to the third power
√x the square root of x the cube root of x % per cent 29 two per cent mill 5‰ five per mill, log x to the base log,o log x to the base 10, common logarithm loge x, Inx. log x, to the base e, natural logarithm, Napierian logarithm ex, exp(x):, exponential function of x, e to the power x the nth power of x, x to the power n x"或x· the nth root of x, x to the power one over n cosine tg, tan tangent ctg. cot cotangent csc. cosec iin arcsin arc sine cos arccos: arc cosine. inh the hyperbolic sine cosh the hyperbolic cosine the summation of xiw*,mothe summation of x sub i, where i goes from 1 to n the product of the product of x sub i, the absolute value of x the mean value of x:x bar xbb b b double prime; b second prime b triple prime f(x) function fof x finite difference or increment △x,bx the increment of x dee x: dee of x: differential x
the differential coefficient of y with respect to r; the first derivative of y with respect of x the second derivative of y with respect of r the nth derivative of y with respect of r dr the partial derivative of y with respect of u, where y is a function of u and another variable (or variables) integral of double integral of n-fold integral of integral between limits a and b(.from a to b) vector F a sub two twenty degrees seven minutes: seven feet thirteen seconds: thirteen inches 0C zero degree Centigrade(Celsius] one [a] hundred degrees Centigrade thirty-two degrees Fahrenheit
第四节符号、公式及其他 、特殊符号 表 1.4 特殊符号 符号 意义符号 意义 because nt y is not greater than uP microprocessor x is not less than mIcrocomputer result in, lead to inches, seconds 4 doesn't result in ∥|alto 》 is much greater than ⊥| is perpendicular to is much less than 8.and is equivalent to I triple integral is similar to t number a pound dollar
、常用希腊字母 小qphi o delta p 三、分数、小数及百分比 /2 a(one)half 0.20(nought, zero) point two 1/3 a(one)third 0.0032 0 point 0 0 three two 1/4 a (one)quarter 63. 57 sixty-three point five seven 1/9 a (one)nineth 52%,52pc fifty-two per cent 2/3 two-third 3%o three per mil(thousand) 5/16 five-sixteenths 2 two and a half 四、符号与方程 a+b and (plus)b Xb es(multiplied by )b a/b a over(divided by )b a equals (is equal to)b a*b a is not (is not equal to)b proximately equals b a is greater than b as<b a is less than or equal to b x-0o x approaches infinity a=b a is equivalent to a is proportional to b a b a to b 90° 90c ninety degrees Centigrate 90F ninety degrees Fahrenheit x2 X y cube (cubed) to the minus tenth v4 the square root of four Va. the cube root of a Va the fifth root of a square
a a double(second, twice) prime f prin differential dz/dx first derivative of z with respect to x y=f (x) y is a function of ay=au the partial derivative of y with respect to u sinh, sh hyperbolic sin logab logarithm b to the base a ae big E is equal to the ratio of p divided by a to e divided by 1, is equal to the ratio of the product p I to the product a e integral of… from n to m the integral of dy (by) the minus y square M=R:X-P(x-a,)M is equal to R sub one multiplied by x minus P sub one, round brackets opened x minus a sub one, round brackets closed b=op sec oB b equals half p secant half beta R=V(EPx)+(EPy )R equals the square root of sigma P x all squared, plus sigma P y all I rad 957. 3 one radian equals one eight degrees divided by pi, which is approximately equal to fifyt-seven point three degrees