Let L be the length of the curve y = f(x), a < x < b, where f is positive and has a continuous derivative. Let Sf be the surface area generated by rotating the curve about the x-axis. If c is a positive constant, define g(x) = f(x) + c and let Sθ be the corresponding surface area generated by the curve y = g(x), a < x < b. Express Sθ in terms of Sf and L.