x11r4 man page for sqrt

SQRT(3) 						     Linux Programmer's Manual							   SQRT(3)

NAME
       sqrt, sqrtf, sqrtl - square root function

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():
	   _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
	       || /* Since glibc 2.19: */ _DEFAULT_SOURCE
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       These functions return 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.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       +-------------------------+---------------+---------+
       |Interface		 | Attribute	 | Value   |
       +-------------------------+---------------+---------+
       |sqrt(), sqrtf(), sqrtl() | Thread safety | MT-Safe |
       +-------------------------+---------------+---------+
CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

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

COLOPHON
       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

								    2017-09-15								   SQRT(3)