1. The problem statement, all variables and given/known data So I'd rather not type out the whole equation I am differentiating with respect to t... Sorry admins. My written work is on the image. I just want to make sure my work is correct. 2. Relevant equations The equation is a differential characteristic equation with cos and sin. 3. The attempt at a solution The attempt solution is on the image. Start at Line 1 to Line 2. I applied product rule twice with chain rule. We are taking the derivative of the formula with respect to t.