sqrt, sqrtf, sqrtl - square root function
#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
These functions return the nonnegative square root of
x.
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.
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.
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
sqrt (), sqrtf (), sqrtl () |
Thread safety |
MT-Safe |
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD, C89.
cbrt(3),
csqrt(3),
hypot(3)