sunos man page for sqrt

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)