First read this: http://www.math.unc.edu/Faculty/pbe/...ations/HW8.pdf

I'll derive the first result (using your notation):

To get , differentiate implicitly with respect to x (use the chain rule on each side):

.

To get , differentiate implicitly with respect to x (use the quotient rule on the right hand side and the chain rule on the left hand side):

.

Therefore .

Now there's a bit of work left for you to do.