関連ワード:
focal length of concave lens is always negative or positive focal length of convex lens is always negative or positive focal length of concave mirror is always negative or positive focal length of convex mirror is always negative or positive focal length of concave lens is negative or positive focal length of concave mirror is negative or positive focal length of convex lens is negative or positive focal length of converging lens is negative or positive focal length of diverging lens is negative or positive focal length of convex concave lens is negative or positive
