(a) x = 50 maximizes the area. We assume that means 50 ft × 50 ft
(b) 2500 ft²
(c) domain: 0 ≤ x ≤ 100; range: 0 ≤ A ≤ 2500
<h3>Step-by-step explanation:</h3>
(a) The function describes a parabola that opens downward. The value of A(x) is zero when x=0 and when x=100. The vertex (maximum) is halfway between those zeros, at x=50. The dimensions are 50 and 100-50 = 50. The maximum area pen will be 50 ft square.
(b) A(50) = (50 ft)² = 2500 ft² . . . the maximum area
(c) A(x) will be negative if x < 0 or x > 100, so the domain is 0 ≤ x ≤ 100.
The value of A(x) ranges from 0 to its maximum, 2500. Hence the range is 0 ≤ A(x) ≤ 2500.
