-1647 Problem 9. Find the smallest possible surface area of a cylindrical can with volume equal to 167 cubic inches. To receive full credit, you should use Calculus techniques to prove that the dimensions you found correspond indeed to the minimum amount of material to be used.

I need assistance with figuring out problems below. I have the complete problem as well as answer but can not figure how the got the answer. Problem#1 A cylinder with a radius of 7 inches and a height of 12 inces. a.) What is the volume of the height if increased by 3 inches. (15)  V= (pie) (r)squared(h) = (3.14)(7)squared(15) =(3.14) (49) (15) = 2307.9( my answer )   2309.07 ( Correct Answer ) HOW DID THEY GET THIS ANSWER

I have an area composite figures geometry problem.

I need help with this question! Thank you so much!