TC's standard MATH FUNCTIONS are contained in the ANSI library. The standard header file math.h contains declarations for these functions:
# include <math.h>
C does not provide an exponentiation operator; instead the standard pow() function is used. This function returns x raised to the power y. If x is negative then y must be integral. Its prototype is:
double pow(double x, double y);
The sqrt() function returns the (double precision) square root of its argument. Most of the common trigonometric functions are also available, returning doubles: sin(), cos(), tan(), asin(), acos(), atan, exp(), log(), log10(), cosh(), sinh(), tanh(). The abs() function computes the absolute value of an integer while fabs() works for doubles.