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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(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99
The sqrt() function returns 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.
C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.
This page is part of release 3.35 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://man7.org/linux/man- pages/. 2010-09-20 SQRT(3)