1. The problem statement, all variables and given/known data Consider that f(x, y) = [sin^2(x − y)] / [|x| + |y|]. Using this, prove: lim(x,y)→(0,0) f(x, y) = 0 2. Relevant equations Definition of a limit, etc. 3. The attempt at a solution I don't know how to start... I've been trying to self-teach limits for a while and Don't know how to do it with the absolute values and two variables. Help is much needed.