Yes, what you have so far, , is correct.
And you "complete the square" just the way you learned many years ago in elementary algebra: To make a "perfect square", you have to add and subtract .
which, as a sum of squares, is never negative.
What does it mean to write Q as a function of and ? Is the following what they are asking for:
Is this correct so far? And how do I need to "complete the square" to show that Q(x)>0? (I don't have any notes on this...)