関連ワード:
is the focal length of a convex lens negative is the focal length of a convex lens negative or positive is the focal length of a concave lens negative is the focal length of a concave lens negative or positive is the focal point of a convex lens negative is the focal length of a convex lens always negative is the focal point of a concave lens negative is the focal length of a concave lens always negative the focal length of a convex lens is always negative or positive the focal length of a convex lens is positive negative zero infinite
