
Differentiate both sides, treating
as a function of
. Let's take it one term at a time.
Power, product and chain rules:



Product and chain rules:




Product and chain rules:




The derivative of 0 is, of course, 0. So we have, upon differentiating everything,

Isolate the derivative, and solve for it:


(See comment below; all the 6s should be 2s)
We can simplify this a bit by multiplying the numerator and denominator by
to get rid of that fraction in the denominator.

Answer:
- FIRSTLY GET THE AREA OF THE WHOLE CIRCLE BY USING FORMULA

- THEN AFTER THAT DIVIDE THE AREA BY 2
- AFTER THAT UR ANSWER WILL COME
<em>PLEASE</em><em> </em><em>MARK ME AS BRAINLIEST</em><em> </em>
3 buckets covers 90m x 80cm = 3 buckets for 90x0.8 = 3 for 72
x buckets covers 200m x 120cm = x buckets for 200x1.2 = x for 240
3/72 = x/240
720 = 72x
x =10 buckets of paint to cover 200mx120cm fence