Hard amplifier problem - Pleease anwer

MarkT:
But its clearly a homework problem you're passing on to us - if you at least had a go at answering
it first it wouldn't be so galling - people like to help, but cheating isn't helping, its avoiding understanding.

It is a challenge from the teacher ..
He said you can get help from anyone .. But I need you to understand the solution ..
I guess nobody knows how to solve it : (