Question

The function f(x) = –(x – 3)2 + 9 can be used to represent the area of a rectangle with a perimeter of 12 units, as a function of the length of the rectangle, x. What is the maximum area of the rectangle?
3 square units
6 square units
9 square units
12 square units

Answer 1

Answer:

9 square units

Step-by-step explanation:

f(x) = -(x - 3)² + 9

= 9 -(x - 3)²

9 minus something, the result is always less than 9, at most equal to 9.

So the maximum f is 9 square units