Question

PLSSSS HELP The area of a cylinder varies jointly with the radius and the height. When the radius is 3 and the height is 6 the area is 36π. Find the are when the radius is 4 and the height is 5

Answer 1

167.55

Explanation:

so it varies jointly so

A-area if cylinder

so

`a \: \alpha \: \pi \: r \: ^(2) h`

so

`a = k\pi \: r^(2)h`

where k is the constant

so apply the first set of values to get k=2/3

then substitute the k with the second set of values