Prove that ,1/v-1/u=1/f

1.	Prove that ,1/v-1/u=1/f
Answer» Object distance (u), image distance (v) and focal length (f) of a spherical lens are related as:1/v – 1/u = 1/f.The formula is a relation between the object distance u, image distance v and the focal length from the pole of the concave mirror. The formula is valid for the images in a convex mirror and even for the images in the lens.We consider the image formed by a concave mirror whose focal length is f and whose radius of curvature is r = 2f.Let P be the pole of the concave mirror. Let P, F , C be the pole, focal point, and centre of curvature along the principal axis. So, PC = 2PF , as r = 2f.\xa0

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