Sorry, another gaming prob!

Ive got this semi-finished game? Anyway…
It’s got the basics, but i just want to know nothing more but how i could fire a bullet in the correct direction of the ship.
Would it be something like duplicate a bullet at ships position, then set it to ships _rotation, then something like:
[AS] xSpeed += speedMath.sin(_rotation(Math.PI/180));
ySpeed += speedMath.cos(_rotation(Math.PI/180));
[/AS] ?
I need some serious help…