Robert J. answered 10/10/13
Tutor
4.6
(13)
Certified High School AP Calculus and Physics Teacher
a) A = xy = x(16-x^2)
b) Domain: (0, 4)
c) A' = 0 => 16-x^2-2x^2 = 0 => x = 4/sqrt(3) gives the largest A = 24.6 units^2
Or you can graph it, and find maximum A at x = 2.3094.