Computes the hyperbolic arcsine of a number.
input value
hyperbolic arcsine
var v = asinh( 0.0 ); // returns 0.0
var v = asinh( 2.0 ); // returns ~1.444
var v = asinh( -2.0 ); // returns ~-1.444
var v = asinh( NaN ); // returns NaN
Computes the hyperbolic arcsine of a number.