I don't understand the steps to solve this

A box with a square base and open top must have a volume of 219488 07713. We wish to find the dimensions of the box that minimize the amount of material used. First, find a formula for the surface area of the box in terms of only 33, the length of one side of the square base. [Hint: use the volume formula to express the height of the box in terms of 33.] Simplify your formula as much as possible. A.) = Next, find the derivative, A'(33). Ala?) : Now, calculate when the derivative equals zero, that is, wher A'(a3) : 0. [Hintz multiply both sides by 322.] A'(a3) = 0 when $ = We next have to make sure that this value of 3: gives a minimum value for the surface area. Let's use the second derivative test. Find A"(zc). Evaluate A"(:c) at the LB-value you gave above. NOTE: Since your last answer is positive, this means that the graph of A(a:) is concave up around that value, so the zero of A'(m) must indicate a local minimum for 44(33)' (Your boss is happy now.)