determine whether $f(x,y)$ converges in $\mathbb{R}$ as $(x,y)\to (0,0)$ in $\mathbb{R}^{2}$. Justify the answer by quoting in full every theorem or exact reference for each.
$$f(x,y) = \begin{cases} 0 & \text{if }y\leq{0}\text{ or } y\geq{x^{2}}\\ \sin(πy/x^{2}) & \text{if}\,0<y<x^{2}\end{cases}$$
