Question

what is the equation of finding focal length of a mirror?
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Answer 1

Answer:

${\huge{\bf{\underbrace{\green{Solution-:}}}}}$

$\blue\implies$${\sf{\red{y+3=10}}}$

$\blue\implies$ ${\sf{\red{y=10-3}}}$

$\blue\implies$ ${\sf{\red{y=7}}}$

${\boxed{\bf{\green{y=7}}}}$

Answer 2

Answer:

1/f= ¹/v+¹/u

the +,- of the u and v depends upon the sign convention.