OMG, I hope I post it in the correct forum, I don't want to get infracted

Heyah, I have this problem to solve, I tried a bit and came to the point where I don't know how to continue. I think I just have to prove my results.. Dunno. I just want to add,that english is not my mother tongue, and I might name some things incorrectly, so just correct my mistake but don't friggin kill me :P . Here it is:

Define all with and:

First I have to simplyfy , so I checked this first :

so I don't have to change the inequality sign:

Here I've changed the inequality sign and I also noticed that:

My next step was this :

So :

and

So it follows:

and this is the point where I don't know how to continue. I mean, I have an example of it in my script but I don't know how to do that. Can someone help?