At what points of \( \mathrm{R}^{2} \) is the following function continuous?
\[
f(x, y)=\left\{\begin{array}{ll}
\frac{\sin \left(9 x^{2}+2 y^{2}\right)}{9 x^{2}+2 y^{2}} & \text { if }(x, y) \neq(0,0) \\
1 & \text { if }(x, y)=(0,0)
\end{array}\right.
\]
