What is principal axis of the mirror?

In the figureshownm the image of a real object is formed at point I. AB is the principal axis of the mirror. The mirror must be

In the figureshownm the image of a real object is formed at point I. AB is the principal axis of the mirror. The mirror must be

A ray of light passing through focus of a concave mirror becomes parallel to the principal axis of the mirror on reflection. Comment. Is the reverse true ?

Answer the following questions: In the case of a concave mirror, show the path of the reflected ray when the Incident ray of light Is parallel to the principal axis of the mirror.

What is the principal axis of a spherical mirror ?