Solve the Problem $A ( x ) = - x ^ { 2 } + 400 x ; \{ x \mid 0 < x < 800 \}$

question 112

Multiple Choice

Solve the problem.
-A farmer has 800 yards of fencing to enclose a rectangular garden. Express the area A of the rectangle as a function of the width x of the rectangle. What is the domain of A?

• A) \(A ( x ) = - x ^ { 2 } + 400 x ; \{ x \mid 0 < x < 800 \}\)
• B) \(A ( x ) = - x ^ { 2 } + 400 x ; \{ x \mid 0 < x < 400 \}\)
• C) \(\mathrm { A } ( \mathrm { x } ) = - \mathrm { x } ^ { 2 } + 800 \mathrm { x } ; \{ \mathrm { x } \mid 0 < \mathrm { x } < 800 \}\)
• D) \(\mathrm { A } ( \mathrm { x } ) = \mathrm { x } ^ { 2 } + 400 \mathrm { x } ; \{ \mathrm { x } \mid 0 < \mathrm { x } < 400 \}\)