Question

f(x)=-2x^2+6x+1
g(x)=x+0.2x^3
x=0
Rotate about the line y=-2

Answer 1

Please, start by sketching both functions. You may have to set f and g equal to each other and then solve the resulting cubic equation for x; these x represent the x-coordinates of the points of intersection of the curves of f and g.

If you haven't yet used the Draw utility, below, I invite you to try it out.

Answer 2

Next, draw the horizontal line y=-2.