Question

write the formula to find the focal length of a concave lens​

Answer 1

Step-by-step explanation:

$\frac{1}{v} - \frac{1}{u} = \frac{1}{f}$

v= image DISTANCE

u= object distance

f= focal length

Answer 2

The distance of the image (D image) and the focal length (F) of the mirror: 1/D object + 1/D image = I/F.

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