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.
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?