how to check the continuity of the function defined by:-

$\displaystyle f(x,y) = \frac{sin(x^2y)}{x^2+y^2} , if (x,y)\neq(0,0)

=0 , if (x,y)=(0,0)$

at (0,0)?

i think it should be done by using polar transformation, but can not do it. any help is appreciated.