1.54 sqrt, sqrtf—positive square root

Synopsis

     #include <math.h>
     double sqrt(double x);
     float  sqrtf(float x);
     

Description
sqrt computes the positive square root of the argument. You can modify error handling for this function with matherr.

Returns
On success, the square root is returned. If x is real and positive, then the result is positive. If x is real and negative, the global value errno is set to EDOM (domain error).

Portability
sqrt is ANSI C. sqrtf is an extension.