Lecture
This lecture covers the relationship between the focal length and the radius of curvature of a concave mirror, based on the reflection law. It explains how light passing through the center of curvature behaves, and how incident light parallel to the principal axis reflects through the focus. By applying geometric approximations, it is shown that the focal length is approximately half of the radius of curvature. Additionally, the lecture discusses the formation of real images for virtual objects in concave mirrors.