Question

The total surface area of a cylinder with height 5 in. is given by the function g(x) = 2πx2 + 10πx, where x is the radius, and the function f(x) = 10πx gives the surface area of the side of the cylinder. Which combined function gives the total surface area of the two bases of the cylinder? A. f + g B. f – g C. g – f D. f · g

Answer 1

• C. g - f

Explanation:

Total surface area of a cylinder with height 5 is:

• A = 2πrh + 2πr² = 10πr + 2πr²

If we substitute r with x, we get:

• g(x) - full surface area
• f(x) - surface area

Total surface area of two bases:

• g - f = 2πx² + 10πx - 10πx = 2πx²

Correct choice is C