Question

Prove that focal length of mirror is half the radius of mirror?

Answer 1

Answer:

Now the angle between the radius of curvature and principal axis will be equal to the angle at which ray is incident and due to reflections law incident angle would be equal to angle cbf. Hence, in both cases Radius is double the focal length.

Answer 2

Explanation:

$Answer$

Now the angle between the radius of curvature and principal axis will be equal to the angle at which ray is incident and due to reflections law incident angle would be equal to angle cbf. Hence, in both cases Radius is double the focal length.