sqrt(3M) Mathematical Library Functions sqrt(3M)
NAME
sqrt, sqrtf, sqrtl - square root function
SYNOPSIS
cc [ 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 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 5.10 1 Nov 2003 sqrt(3M)
