Re: Derive the expression

Hey bobred.

Hint: Try dividing C+D from RHS and multiplying A-B from LHS.

Re: Derive the expression

Hi, I've done that but still drawing a blank, I keep going round in circles. Going to have a break.

Re: Derive the expression

Sorry, is there another small hint?

Re: Derive the expression

Can you try squaring the terms and simplifying to show that the result holds? (In other words, square both sides and collect together)

Re: Derive the expression

Hi, got it, was staring me in the face, many thanks. Bob