acos(), acosf()

Compute the arccosine of an angle

Synopsis:

#include <math.h>

double acos( double x );

float acosf( float x );

Library:

libm

Description:

These functions compute the arccosine (specified in radians) of x.

Returns:

The arccosine in the range (0, PI).

Examples:

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

int main( void )
{
    printf( "%f\n", acos(.5) );

    return EXIT_SUCCESS;
}

produces the output:

1.047197

Classification:

ANSI

See also:

asin(), atan(), atan2()