I must find df(0,0)/dx and df(0,0)/dy, using the definition of the partial derivative of the limit. With;
f(x,y) = (y*x^2)/(x^2+y^2) for (x,y) not (0,0) and
f(x,y) = 0, when (x,y) = (0,0)
I really have no idea how to solve this...
btw, is there an option to write LaTeX code here ?