sqrt, sqrtf, sqrtl - square root function
#include <math.h>
double sqrt(double x);
float sqrtf(float x);
long double sqrtl(long double x);Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions return the nonnegative square root of x.
On success, these functions return the square root of x.
If x is a NaN, a NaN is returned.
If x is +0 (-0), +0 (-0) is returned.
If x is positive infinity, positive infinity is returned.
If x is less than -0, a domain error occurs, and a NaN is returned.