sqrt(), sqrtf(), sqrtl()

Calculate the nonnegative square root of a number

Synopsis:

#include <math.h>

double sqrt( double x );

float sqrtf( float x );

long double sqrtl( long double x );

Arguments:

x
The number that you want to calculate the square root of.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

These functions compute the nonnegative square root of x. A domain error occurs if the argument is negative.

Returns:

The nonnegative square root of the given number. For finite values of x < -0, these functions return NaN. The return value when x is -Inf is NaN.

If an error occurs, these functions return 0, but this is also a valid mathematical result. If you want to check for errors, set errno to 0, call the function, and then check errno again. These functions don't change errno if no errors occurred.

Examples:

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

int main( void )
  {
    printf( "%f\n", sqrt(.5) );
    return EXIT_SUCCESS;
  }

produces the output: 

0.707107

Classification:

ANSI, POSIX 1003.1

Safety:
Cancellation point No
Interrupt handler No
Signal handler No
Thread Yes

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