I have the expression $A\cos(wt) + B\sin(wt)$ and I need to write it in the form $r\sin(wt - \theta)$. I know how to do this for the cosine form (i.e., $R\cos(wt - \delta)$, but I'm not sure how to make it into a sine. I'm sure it's some simple algebra manipulation that I'm missing...
(in response to the answer below: r=R. and $\delta = \theta + (4n + 1) \pi /2$. that's the answer but i don't know how to get there)
$$R \cos(wt-\theta)=R \sin \left( \frac{\pi}{2}-wt+\theta \right)=-R \sin \left( wt-\theta-\frac{\pi}{2} \right) $$