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Yes, this point is the focal point of the mirror. A concave mirror will focus all light parallel to the OA through this point.
Measure the distance from f to the apex. This is the focal length.
How are the focal length and the radius of the curve related? (HINT: measure C - apex)

Also notice that if you were to reverse the reflected and incident rays, then any light passing through f will reflect parallel to the OA.

We will use this kind of symmetry of the concave mirror to develop a set of 4 Easy Rays to help us determine the characteristics of an image formed by any object formed by an obfect on the OA.

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