1. The problem statement, all variables and given/known data Is the function f(x,y) defined by f(x,y) = (yx^3 - 3y^3)/(x^2 + y^2), (x,y)!=(0,0) =0, (x,y)=(0,0) continuous everywhere in R^2? Give reasons for your answer. 2. Relevant equations 3. The attempt at a solution I changed f(x,y) into polar coordinates and found the limit as r->0, which is 0. I also found that f(x,0) = 0, f(0,y) = -3y^2 -> 0 as y->0, and f(x,x)= -infinity. However I'm not sure if I've done the question right or if this is enough working.