fabs, fabsf, fabsl - compute absolute value of floating-point number

Syntax	#include <math.h> double fabs(double x); C11 float fabs(float x); long double fabs(long double x); (End)
Description	These functions compute the absolute value of the floating-point number x.
Return val.	Absolute value of the floating-point number x if successful.
See also	abs(), cabs(), ceil(), floor(), math.h.