Question

Denote the length, width, and height of the box by , , and , respectively (). It is given that . We have to make the surface area as small as possible.

Answer 1

Denote the length, width, and height of the box by x, y, and z, respectively (x,y,z > 0). It is given that xyz=110. We have to make the surface area [S]=2xy+2xz+2yz as small as possible.

Answer 2

Write z by x and y, insert it in the function you are trying to minimize and then find local minima through the derivatives.