Volume = x(70 - 2x)(30 - 2x)
= x(2100 - 200x + 4x^2)
= 2100x - 200x^2 + 4x^3
Volume' = 2100 - 400x + 12x^2
12x^2 - 400x + 2100 = 0
6x^2 - 200x + 1050 = 0
x1 = 6.5 x2 = 26.8
Lenght = 57 in
width = 17 in
height = 6.5
Max volume = 6298.5 in^3
7.6m questions
10.2m answers