# Hacoversine > Compute the half-value [coversed sine][coversed-sine].
The half-value [coversed sine][coversed-sine] is defined as
Half-value coversed sine.
## Usage ```javascript var hacoversin = require( '@stdlib/math/base/special/hacoversin' ); ``` #### hacoversin( x ) Computes the half-value [coversed sine][coversed-sine] (in radians). ```javascript var v = hacoversin( 0.0 ); // returns 0.5 v = hacoversin( 3.141592653589793/2.0 ); // returns 0.0 v = hacoversin( -3.141592653589793/6.0 ); // returns 0.75 ```
## Examples ```javascript var linspace = require( '@stdlib/array/linspace' ); var TWO_PI = require( '@stdlib/constants/float64/two-pi' ); var hacoversin = require( '@stdlib/math/base/special/hacoversin' ); var x = linspace( 0.0, TWO_PI, 100 ); var i; for ( i = 0; i < x.length; i++ ) { console.log( hacoversin( x[ i ] ) ); } ```