<PRE><B>Question 256816</B>
.


The goal of my post is to &amp;nbsp;DISPROVE &amp;nbsp;the solution by other tutor,

given long time ago &amp;nbsp;(probably, &amp;nbsp;20 &amp;nbsp;years ago).



The problem is about hyperbolic mirror, &amp;nbsp;but the other tutor solves it for parabolic mirror,

without any explanations, &amp;nbsp;why he &amp;nbsp;(or she) &amp;nbsp;solves different problem.



So, &amp;nbsp;ignore that solution as &amp;nbsp;IRRELEVANT.



//////////////



I looked at other solutions of this tutor and noticed that they are quite accurate 

and are written in good style; &amp;nbsp;so, &amp;nbsp;this case looks like a random accident . . . 



</PRE>