Thursday, 26 December 2013

multivariable calculus - Show that fracsin(xy)y is differentiable at (0,0).

How do I show that the following function is differentiable at (0,0)?
{sin(xy)y,if y00,if y=0


I calculated the partial derivatives and





  • f(x)=cos(xy) exists near (0,0) and is continuous

  • f(y)=xycos(xy)sin(xy)y2 exists, but how do I show that it is continuous?

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