00:01
All right, so we have a box.
00:03
We have actually a box with square base, with square base, all right? so maybe it looks something like this.
00:14
So this is a box, it is square base.
00:18
So just let me, yeah.
00:24
And the height of the box is h and but base is square.
00:27
So that means this is x and this is also x.
00:30
The cost per square feet for the top and bottom actually top and bottom is the squares of area x squared because area of square is x squared so what is total area of top and bottom two x squared and it is into 20 because for one square foot it is 20 so 20 this thing the cost 20 cents so it is 40 x square cents 40 x square cents is the cost of top and bottom whereas the side there are four sides so you can treat the four sides as walls of the box.
01:02
What is the area of each wall? xh because it's a rectangle xh.
01:06
Xh, 4xh into 8 because 8 is the 8 number of sense.
01:12
So 32 xh sense.
01:14
All right.
01:15
So the total cost is a function of both x and h is 40 x squared plus 32 xh.
01:24
Also it's given the volume of the box is 20...