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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)