The derivative of x^3 is 3x^2.... is that what you were looking for?
Volume of a cylinder is pi*(radius)^2* height. pi is 3.14 and radius is half of diameter which would be 3. height is 8. Thus volume of a cylinder in your case is pi*9*8 or 72*pi which is approximately 226.19
<h2>The opposite of an opposite of a integer is the original integer.</h2>
First, we determine the volumes of the posts may it be cylindrical in shape or rectangular prism.
(A) cylindrical:
( π(26.7/100)² - π(24.2/100)²)*(7.5) = 0.3 m³
(B) rectangular prism:
(40/100)²(7.5) - (35/100)²(7.5) = 0.28125 m³
Then, we calculate for the amount of substance
(A) cylindrical: (0.3 m³)(2700 kg/m³) = 810 kg
(B) rectangular prism : (0.28125 m³)(2700 kg/m³) = 759.375 kg
Then, calculate for the costs
(A) (810 kg)($0.38/kg) = $307.8
(B) (759.375 kg)($0.38/kg) = $288.56
Thus, the answer for A is rectangular post
B. About $19.24 can be saved.
A 31 inches is the answer because it can't be higher than 39