1. The problem statement, all variables and given/known data Due to illness, I missed my calculus class and can't do the homework my friend gave me. Q1) The volume of a sphere is increasing at a rate of 75cm^3s^-1. Find the rate at which the radius is increasing at the instant when the radius of the sphere is 15cm. Q2) Find the gradient of the curve y=5e^3x at the point for which x=ln a, giving your answer in simplified form in terms of the constant a. 2. Relevant equations 3. The attempt at a solution Q1) First idea was to use the chain rule? Q2) y=5e^3x, dy/dx=15e^3x. Substitute x=ln a and rearrange to find a?