sqrt


SYNOPSIS
       #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)):

       sqrtf(), sqrtl():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99

DESCRIPTION
       The sqrt() function returns the nonnegative square root of x.

RETURN VALUE
       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.

ERRORS
       See math_error(7) for information on how to determine whether an  error
       has occurred when calling these functions.

       The following errors can occur:

       Domain error: x less than -0
              errno  is  set  to  EDOM.   An  invalid floating-point exception
              (FE_INVALID) is raised.

CONFORMING TO
       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4,
       4.3BSD, C89.

SEE ALSO
       cbrt(3), csqrt(3), hypot(3)

COLOPHON
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