Question

A child holds a candy bar 13.4 cm in front of the convex side-view mirror of an automobile.
The image height is reduced by one fifth.
What is the radius of curvature of the mirror?
Answer in units of cm.

I did 1/5=-image distance (i)/13.4-->i=-2.68
1/f=1/-2.68+1/13.4---->-3.35
|f|*2=r
r=6.7cm
but this was not the right answer. Where did I go wrong/ how do you solve?

Answer 1

f=2/r bruh