I need to show that for any approximation around the point (0, 0) is valid:
$$\lim _ { x \rightarrow 0 , y \rightarrow 0 } \frac { \sin ( x y ) } { x y } = 1$$
I know how to do Taylor series approximation for functions of one variable, but this kind of multivariable function is new to me.
And also can you suggest me some literature that covers this topic?
Any help/hint is appreciated.
Thanks in advance.