4. A circle with radius one centered at (0, 2) is revolved about the line " - 2. The solid of revolution is a torus. Find the volume of torus. Provide at heat sketch of the solid and an element of volume for full mark. 5. a) Find the arc length of the function y # In(1 - 27) in the interval 0. b) Find the function f(r) so that, for a 2 0, its are length in the interval 10, I] is equal to 2. + f(x)