a Write the integral that gives the area of the surface generated when the curve is revolved about the given axis b Use a calculator or software to approximate the surface area y 2 cos x for 0 x about the x axis R a Choose the correct answer below x 7 2 2 S 0 x 7 OB 2n S 2 cos x 1 4 sin x dx 0 OA 2n 2 cos x 1 4 sin x dx x 7 OC 2 cos x1 0 2 cos x1 4 sin x dx 7 OD 2 S 2 cos x1 4 cos x dx 0