# Question #586de

##### 1 Answer
Mar 6, 2017

The distance between two parallel mirrors is $l$

The point $O$ is placed at a distance $\frac{l}{3}$ from a mirro.

So the distance of point $O$ from other mirror will be $l = \frac{l}{3} = \frac{2 l}{3}$

Hence the distance between any two images in the second mirror is $\ge \left(l + \frac{l}{3} - \frac{2 l}{3}\right) = \frac{2 l}{3}$

Hence the distance between any two images in the 1st mirror is $\ge \left(l + \frac{2 l}{3} - \frac{l}{3}\right) = \frac{4 l}{3}$

The distance between the first mimage of first mirror and the first image of second mirror is

$= \frac{l}{3} + l + \frac{2 l}{3} = 2 l$

So the distance between any two images can not be $< \frac{2 l}{3}$