Derive mirror formula for a convex mirror

derive mirror formula for a convex mirror.

Let AB be an object placed on the principal axis of a convex mirror of focal length f. u is the distance between the object and the mirror and v is the distance between the image and the mirror.
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But DE = AB and when the aperture is very small EF = PF.
Equation (2) becomes
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From equations (1) and (3) we get
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[PF = f, PB1 = v, PB = u, PC = 2f]

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Dividing both sides of the equation (4) by uvf we get

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