1. By the chain rule,

I'm going to switch up the notation to save space, so for example,
is shorthand for
.

We have




Similarly,

where



To capture all the partial derivatives of
, compute its gradient:


2. The problem is asking for
and
. But
is already a function of
, so the chain rule isn't needed here. I suspect it's supposed to say "find
and
" instead.
If that's the case, then


as the hint suggests. We have



Putting everything together, we get


X/28 = 5/7
x = 28 * 5 / 7
x = 20
answer
x = 20 ft
Answer:10x^2y^2
Step-by-step explanation:
5x2 X 2y2=10x^2y^2




Hope this helps!
Thank you for posting your question at here on Brainly.
-Charlie