How to find focus and 2F with focal length​

The values of u and v will be same for point A. So the coordinates of Point A must be (- 2f, 2f), because for a convex lens, when u =-2f, v=2f. Hence , half the value of either coordinate of A (i.e., distance OB) gives the focal length of the convex lens.

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explanation:

no

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