Question

Suppose a tin box is to be constructed with a square base, an open top and a volume of 32 cubic inches. The cost of the tin to construct the box is $0.15 per square inch for the sides and $0.30 per square inch for the base.

a) The minimized cost of the tin box is

b) The cost is minimized at critical point x=a because the first derivative test found that

• A. $$f'(x)\text{ was negative to the left of x=a and positive to the right}$$
• B. $$f''(a)>0$$
• C. $$f'(x)\text{ was positive to the left of x=a and negative to the right}$$
• D. $$f'(a)=0$$
• E. $$f''(a)<0$$

Answer 1