Question

why we take here,- sign in 1/v-1/u=1/f


becoze the mirror formula is

1/f=1/v+1/u​

Answer 1

Answer:

You are little confused it seems, dear it is lens formula which is,

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

and this is absolutely correct.

Whereas Mirror formula as you stated is very right. , which is,

$\frac{1}{v} \: \: + \: \: \frac{1}{u} \: \: \: \: = \frac{1}{f}$

...