Arccovercosine

Compute the inverse coversed cosine.

The inverse coversed cosine is defined as

Usage

var acovercos = require( '@stdlib/math/base/special/acovercos' );

acovercos( x )

Computes the inverse coversed cosine.

var v = acovercos( 0.0 );
// returns ~1.5708

v = acovercos( -3.141592653589793/2.0 );
// returns ~-0.6075

v = acovercos( -3.141592653589793/6.0 );
// returns ~0.4966

If x < -2, x > 0, or x is NaN, the function returns NaN.

var v = acovercos( 1.0 );
// returns NaN

v = acovercos( -3.14 );
// returns NaN

v = acovercos( NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/array/base/linspace' );
var acovercos = require( '@stdlib/math/base/special/acovercos' );

var x = linspace( -2.0, 0.0, 100 );

var i;
for ( i = 0; i < x.length; i++ ) {
    console.log( acovercos( x[ i ] ) );
}

C APIs

Usage

#include "stdlib/math/base/special/acovercos.h"

stdlib_base_acovercos( x )

Computes the inverse coversed cosine of a double-precision floating-point number.

double out = stdlib_base_acovercos( -3.141592653589793/2.0 );
// returns ~-0.6075

The function accepts the following arguments:

x: [in] double input value.

double stdlib_base_acovercos( const double x );

Examples

#include "stdlib/math/base/special/acovercos.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { -2.0, -1.80, -1.78, -1.67, -0.56, -0.27, -1.67, -0.78, -1.89, 0.0 };
    
    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_acovercos( x[ i ] );
        printf( "acovercos(%lf) = %lf\n", x[ i ], v );
    }
}