| -0 | errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised. |
NAME
sqrt, sqrtf, sqrtl - square root function
LIBRARY
Math library (libm, -lm)
SYNOPSIS
#include <math.h>double sqrt(double \nx\n);\n
\nfloat sqrtf(float \nx\n);\n
\nlong double sqrtl(long double \nx\n);sqrtf(), sqrtl():
\n
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
\n
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
\n
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCEDESCRIPTION
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 |
STANDARDS
C11, POSIX.1-2008.
HISTORY
C99, POSIX.1-2001.
The variant returning double also conforms to SVr4, 4.3BSD, C89.
SEE ALSO
cbrt(3), csqrt(3), hypot(3)