1. I am supposed to find dx and dy. I think I am missing a step or a general idea. I spent quite some time figuring out what rules should I use and the only sequence I can think of is quotient rule and chain on the (x2 +y2)1/2 term. The answer that I find is ((xy(3x2+2y2))/(x2+y2)3/2 . On the other hand I found that wolfram alpha solves it with the y'(x) term that I cannot understand, since it should find the only x terms. Please find the attached wolfram alpha solution. I am not asking for a solution (step by step) just some guidance. Here is a link to the wolfram alpha's solution : http://i1375.photobucket.com/albums...x2ysqrtx2y2_--2015-04-20_1952_zpskiujuryl.jpg The solution given is:((xy(x2+2y2))/(x2+y2)3/2 Thanks you!