Ok first we can split it in two :

and

.
The derivative of

is 3.
For the first part, we use the chain rule :
![[f(g(x))]'=g'(x)f'(g(x))](https://tex.z-dn.net/?f=%5Bf%28g%28x%29%29%5D%27%3Dg%27%28x%29f%27%28g%28x%29%29)
hence

(since the derivative of the exponential is itself) hence
So, if I'm understanding you correctly, f(x)=x^2 divided by 3x+x, or
f(x) = (x^2)/(3x+x)
f(6) --> plug the 6 in to all values of x --> f(6) = (6^2)/(3×6 + 6) = 36/(18+6)
= 36/24 --> both are divisible by 12, so 36/12=3 and 24/12=2, now we have the reduced (simplified) answer:
f(6) = 3/2, or 1 1/2, or 1.5
The predicted value of hardness at 37 hours is 243.87 and an 85% confidence interval for the mean hardness is (242.12, 245.61). At 41 hours, the predicted hardness is 252 and an 85% confidence interval for mean hardness is (249.83, 254.18). The confidence interval for X is equals to 41 which is wider because the value 41 is farther away from the sample mean X than is 37. As an outcome, the standard error for the prediction is larger.
Well, that means that the sides and top are toutching the sphere
radius of sphere=10 so radius of cylinder=10
the height is the diameter or 20
V=hpir^2
v=20pi10^2
v=20pi100
v=2000pi
answer is D