The diagram below shows a diagram of a compound thin lens system consisting of two thin lenses separated by the distance d. The object to the compound lens is o, and the image to the compound lens is i.. a. Derive the analytical expression for the image i, in terms of the lens parameters f, f, d and o. Hint: Use the thin lens formula to find the image of the first lens and then use this image as the object for the second lens. b. If we let i, go to infinity, o, takes on the value designated by the abbreviation f.f.l. (front focal length). Using the expression for the image distance of a compound lenses, find the expression for the f.f.l. c. If we let o, go to infinity, i, takes on the value designated by the abbreviation b.f.l. (back focal length). Using the expression for the image distance of a compound lenses, find the expression for the b.f.l. 02