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NAME
sqrt, sqrtf, sqrtl - square root function
LIBRARY
Math library (libm, -lm)
SYNOPSIS
#include <math.h> double sqrt(double x); float sqrtf(float x); long double sqrtl(long double x); 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 <= 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 │ └───────────────────────────────────────────────────────────────┴───────────────┴─────────┘
STANDARDS
C99, POSIX.1-2001, POSIX.1-2008. The variant returning double also conforms to SVr4, 4.3BSD.
SEE ALSO
cbrt(3), csqrt(3), hypot(3)