Hi, I'm having trouble solving part c of the following question.

Let where a is a real constant.

a.Show that

This part I'm fine with as

b.Find the values of for which

I get for this part.

c.Let where and are non-zero real constants. If for and all roots of satisfy , find the values of and and show that these are the only possible values.

Stuck on this part of the question...

Thanks for your help!