22) a) let the base of the rectangle be x
Area = Base x Height
200 = x(height)
height = 200/x
Perimeter = 2(height) + 2(base)
since there is already an existing wall, get rid of one of the sides
L = 2(base) + height
L = 2x + 200/x
b) L' = 2 -200/x^2
= 2(1-100/x^2)
L" = 400/x^3
At L' = 0
0 =...