phasor equation using Euler to rectangular
The only difference between sine and cosine is a 90 degree phase shift.  So you can very easily rewrite that sine as a cosine, all you need to do is adjust the phase appropriately.  

$$ \sin(\theta) = \cos\left(\theta - \frac{\pi}{2}\right) $$

However, I will also note that usually omega is an angular frequency measured in radians instead of degrees, so make sure to keep your units consistent!