Question

A mirror forms an image double the size of the object what is it focal length. Prove This Question Mathematically.

Answer 1

$\huge\underline\bold\color{blue}{Answer}$

⟹Here u=−20cm,

⟹m=−2

⟹Now, m= −v/u ⟹−2= v/20 ⟹v=−40

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Answer 2

Here u=−20cm,

⟹m=−2

⟹Now, m= −v/u ⟹−2= v/20 ⟹v=−40