This is supposed to be year1 calculus question but I can't answer it.(adsbygoogle = window.adsbygoogle || []).push({});

If f:R_2-->R is 0 if (x,y)=(0,0) and xy(x_2-y_2)/(x_2+y_2) otherwise then evaluate 2nd order partial derivative DxDyf(0,0) and Dy,Dxf(0,0)

The thing is, I get some complicated looking expression for DxDyf(x,y) and I can't simply put x=0 and y=0 in that expression right? because it gives 0/0... What am I misunderstanding here?

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# Homework Help: Easy partial differentiation

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