Hii Tiny tim,thnx for ur warm welcome,
Now I continue my problem=
In this Ques.—f(x,y)={|xy|}1/2 Not differentiable at (0,0)
I find out Both Partial derivative fx and fy and solve the ques.
But in that ques.== f(x,y)= xy /√(x2+y2)
in my book method is diffrent.
in that ques method is to...