1. ## Second Derivative

h"(0) if h(t) = (sin(2t) + cos(3t))^5

I've done the first derivative which is

h'(t) = 5(sin(2t) + cos(3t))^4(2cos(2t)-3sin(3t))

I need I little help getting the second derivative, but that isn't my main concern, I just wanted to know if I had to plug in 0 after finding the second derivative. For the second derivative, do I still need to use the chain rule, or do I need to use the product rule and the chain rule?

2. Take the derivative of the derivative as you would if the function was f(x)=x^3. They are asking for the rate of change of the slope at x=0; i.e. - plug and chug.

3. Ok, so what exactly do I use to find the second derivative? Do I need to just use the chain rule, or do I need to use the chain rule and the product rule?