sqrt(3M) Mathematical Library Functions sqrt(3M)NAME
sqrt, sqrtf, sqrtl - square root function
SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include <math.h>
double sqrt(double x);
float sqrtf(float x);
long double sqrtl(long double x);
DESCRIPTION
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 < −0, 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 −Inf, a domain error occurs and a NaN is returned.
ERRORS
These functions will fail if:
Domain Error The finite value of x is < −0 or x is −Inf.
If 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.
USAGE
An application wanting to check for exceptions should call feclearex‐
cept(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 ALSOfeclearexcept(3M), fetestexcept(3M), isnan(3M), math.h(3HEAD),
attributes(5), standards(5)SunOS 5.11 12 Jul 2006 sqrt(3M)
