Find the volume of the solid of revolution generated by revolving the region bounded by the graphs of the given equations about the indicated line.
y = e^x, y = 0, x = 0, x = 3, about y = -6
using discs of thickness dx,
v = ∫[0,3] π(R^2-r^2) dx
where r = 6 and R = 6+y
v = ∫[0,3] π((6+e^x)^2-(6)^2) dx