function cotd( x ) {
	return addon( x );
}
Computes the cotangent of an angle measured in degrees.

@private
@param {number} x - input value (in degrees)
@returns {number} cotangent

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

@example
var v = cotd( 45.0 );
// returns 1.0

@example
var v = cotd( 90.0 );
// returns 0.0

@example
var v = cotd( 60.0 );
// returns ~0.58

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