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AIX Version 4.3 Base Operating System and Extensions Technical Reference, Volume 2

sqrt, sqrtl, or cbrt Subroutine

Purpose

Computes square root and cube root functions.

Libraries

IEEE Math Library (libm.a)

or System V Math Library (libmsaa.a)

Syntax

#include <math.h>
double sqrt (x)
double x;
long double sqrtl (x)
long double x;
double cbrt (x)
double x;

Description

The sqrt subroutine, sqrtl subroutine, and cbrt subroutine compute the square root and cube root, respectively, of their parameters.

Note: Compile any routine that uses subroutines from the libm.a library with the -lm flag. To compile the sqrt.c file, for example, enter:
cc sqrt.c -lm

Parameters

x Specifies some double-precision floating-point value.

Return Values

The sqrt (-0.0) = -0.0.

The sqrtl (-0.0) = -0.0.

Error Codes

When using libm.a (-lm):

For the sqrt subroutine, if the value of x is negative, a NaNQ is returned and the errno global variable is set to a EDOM value.

When using libmsaa.a (-lmsaa):

For the sqrt and the sqrtl subroutines, if the value of x is negative, a 0 is returned and the errno global variable is set to a EDOM value. A message indicating a DOMAIN error is printed on the standard error output.

These error-handling procedures may be changed with the matherr subroutine when using the libmsaa.a (-lmsaa) library.

Implementation Specifics

These subroutines are part of Base Operating System (BOS) Runtime.

The cbrt subroutine is not part of the ANSI C Library.

Related Information

The exp, expm1, log, log10, log1p, or pow subroutine.

Subroutines Overview AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.

128-Bit long double Floating-Point Format AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.


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