Arcvercosine

Compute the inverse versed cosine.

The inverse versed cosine is defined as

a v e r c o s left-parenthesis theta right-parenthesis equals arc cosine left-parenthesis 1 plus theta right-parenthesis

Usage

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

avercos( x )

Computes the inverse versed cosine.

var v = avercos( 0.0 );
// returns 0.0

v = avercos( -Math.PI/2.0 );
// returns ~2.1783

v = avercos( -Math.PI/6.0 );
// returns ~1.0742

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

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

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

v = avercos( NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/math/utils/linspace' );
var avercos = require( '@stdlib/math/base/special/avercos' );

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

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