A plane mirror is also known as a divergent mirror, as stated in the reference material.
While the primary function of a plane mirror is reflection without convergence or divergence of light rays in the ideal sense, the term "divergent mirror" might be used in some contexts, perhaps to highlight how reflected light from a non-ideal plane mirror spreads out slightly due to imperfections on the surface. The term "divergent mirror" is also generally associated with convex mirrors, not plane mirrors.
Therefore, the answer extracted from the provided reference is that a plane mirror is also known as a divergent mirror. However, this usage can be misleading and less common than calling it simply a plane mirror.
