The volunteers here are happy to HELP, but I think you misunderstand what they do. They do not provide answers, rather they assist you as YOU solve the problem.

In the future, please:

(1) provide one problem per thread;

(2) show what work you have done, or if you have not done any, give a brief description of why you cannot even start; and

(3) put your thread in an appropriate forum so that the right volunteers will see it. This thread belongs in calculus or pre-calculus, not algebra.

As for your first problem, use implicit differentiation to find the derivative, and simply plug in the given numbers for x and y. Show us your differentiation and answer so we can make sure you made no mistakes. (I am presuming this problem would not have been assigned without explaining implicit differentiation. If that assumption is incorrect, please tell us that the topic in unknown to you, and we shall go from there.)

As for the second problem, "consider" the function? What does that even mean, to ponder on its significance like a Zen koan?