The image of an object, formed by a combination of a convex lens (of focal length f) and a convex mirror (of radius of curvature R), set up, as shown, is observed to coincide with the object.
Redraw this diagram to mark on it the position of the centre of curvature of the mirror.
Obtain the expression for R in terms of the distances, marked as a and d, and the focal length f, of the convex lens.
