function invf( x ) {
	return float64ToFloat32( 1.0 / float64ToFloat32( x ) );
}
Computes the multiplicative inverse of a single-precision floating-point number `x`.

@param {number} x - input value
@returns {number} multiplicative inverse

@example
var v = invf( -1.0 );
// returns -1.0

@example
var v = invf( 2.0 );
// returns 0.5

@example
var v = invf( 0.0 );
// returns Infinity

@example
var v = invf( -0.0 );
// returns -Infinity

@example
var v = invf( NaN );
// returns NaN