Question

A concave mirror has a focal length of 12 cm at what distance should the object from mirror be placed so that it forms an image at 8 cm from the mirror?​

Answer 1

Explanation:

Given f= -12

v= -8 and u=?

1/f= 1/v+ 1/u

-1/12= -1/8+1/u

-1/12+1/8=1/u

(3-2)/24=1/u

1/24=1/u

u=24