c语言系统函数（C language system function）.docVIP

c语言系统函数（C language system function） Mathematical function math.h 1, integer absolute function [function head]int ABS (int x) [return value] the absolute value of the parameter x (integer) (|x|). [description] the return value of this function is 0~32767. If the value of X is -32768, the return value is -32768. 2, long integer absolute value function [function head]long labs (long x) [return value] the absolute value of the parameter x (long integer) (|x|). 3. Realistic absolute value function [function head]double Fabs (double x) [return value] the absolute value of the parameter x (real type) (|x|). 4, seek less than or equal to the maximum integer function of X [function head]double floor (double x) [return value] the maximum integer less than or equal to the parameter X. 5. Seek the smallest integer function greater than or equal to X [function head]double ceil (double x) [return value] the smallest integer greater than or equal to the parameter X. 6, positive square root function [function head]double sqrt (double x) [return value] the positive square root of argument x. [indicates that the value of]x should be greater than or equal to O. 7, for common logarithmic function [function head]double log10 (double x) [return value] the common logarithm of parameter X (log10x). [description]x should be 0. 8, the natural logarithm function [function head]double log (double x) [return value] the natural logarithm of parameter x (LN, X). [description]x should be O. 9, for exponential function [function head]double exp (double x) [return value] the exponent X of parameter ex. 10, find the X 1O quadratic function [function head]double pow10 (int x) [return value]10, x, 10x. 11, find the Y x quadratic function [function head]double pow (double, x, double, y) [return value] parameter x, y th (XY). [description] x and y were not O or X is less than or equal to 0, and two Y is not an integer. 12, sine function [function head]double sin (douhle x) [return value] the sine value o