1. The problem statement, all variables and given/known data Using polar coordinates, show that lim (x,y)->(0,0) [sin(x^2+y^2)]/[x^2+y^2] = 1 2. Relevant equations r^2=x^2+y^2 3. The attempt at a solution I was able to get the limit into polar coordinates: lim r->0^+ [sin(r^2)]/r^2 but I'm not sure how to take this limit. I tried L'Hospital's, but it was just messy and useless seeming. So, any hints?