Derive the image distance by using mirror equation...help in finding this.

pls post complete ques

1/f=1/u+1/v then 1/v=1/f-1/u so finally v=u-v/u.. This is the answer for the question being asked. First derive the mirror formula or mirror equations then you get a relationship between focus image distance and object distance Then you can isolate the image distance separately by transposing object distance to other side then continue subtracting inverse of focal length and object distance...