# sqrt(3) [v7 man page]

SQRT(3) Linux Programmer's Manual SQRT(3)NAME

sqrt, sqrtf, sqrtl - square root functionSYNOPSIS

#include <math.h> double sqrt(double x); float sqrtf(float x); long double sqrtl(long double x); Link withFeature 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-lm.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, a domain error occurs, and a NaN is returned.-0ERRORS

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 thanerrno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.-0ATTRIBUTES

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)

## Check Out this Related Man Page

sqrt(3M) Mathematical Library Functions sqrt(3M)NAME

sqrt, sqrtf, sqrtl - square root functionSYNOPSIS

c99 [ flag... ] file...[ library... ] #include <math.h> double sqrt(double x); float sqrtf(float x); long double sqrtl(long double x);-lmDESCRIPTION

These functions compute the square root of their argument x.RETURN VALUES

Upon successful completion, these functions return the square root of x. For finite values of x <, a domain error occurs and either a NaN (if supported) or an implementation-defined value is returned. If x is NaN, a NaN is returned. If x is +-0 or +Inf, x is returned. If x is-0, a domain error occurs and a NaN is returned.-InfERRORS

These functions will fail if: Domain Error The finite value of x is <or x is-0If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the invalid floating-point exception is raised. The sqrt() function sets errno to EDOM if the value of x is negative.-Inf.USAGE

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions. An application can also set errno to 0 before calling sqrt(). On return, if errno is non-zero, an error has occurred. The sqrtf() and sqrtl() functions do not set errno.ATTRIBUTES

See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+SEE ALSO

feclearexcept(3M), fetestexcept(3M), isnan(3M), math.h(3HEAD), attributes(5), standards(5)SunOS 5.1112 Jul 2006 sqrt(3M)