Task id16597

A convex mirror is placed on the path of the converging light beam so that the point of convergence of this beam is on the main optical axis of the mirror, behind it, at a distance d = 30 cm from the pole. After installing the mirror, the reflected light beam converged in front of the mirror at a distance f = 50 cm from the pole. Find the radius of curvature of the mirror. What should be the radius of curvature of the mirror so that not the reflected rays themselves, but their extensions, converge at the same distance behind the mirror?