00:01
So it is safe to minimize the construction cost.
00:02
So we need to minimize construction cost.
00:10
Now the company is planning to construct a warehouse whose entire volume is 252 ,000 feet cube.
00:16
So volume is 252 ,000 feet cube.
00:20
Then construction costs per square foot are estimated to be as follows.
00:24
So for wall, now let's consider that house is a cube.
00:31
So walls cost, which is this four sides.
00:35
So four walls we have.
00:37
So walls cost is $3.
00:40
Okay.
00:41
So this is per square feet cost.
00:43
Now next is, so let's write here, wall cost is $3 per square feet.
00:48
Then we have floor cost as $4 per square feet and then ceiling cost.
00:54
$3 per square feet.
00:56
Now the total cost of the function is given a c of x, y, z where x, y, z represent height.
01:04
Length width and height so this is length this is width and this is height so now let's calculate the total cost so total cost will be the area since this is per unit area cost so wall so wall has height and width and then height and length okay so two walls are with height and with this one and this one and two walls with with height and length so we have two times height into width so that is height is z and width is y similarly two times height is z and length is x.
01:44
Now cost of this is wall is $3.
01:47
So this will be $3 and this will also be $3.
01:50
Now next we have one floor which has length and width.
01:55
So length is x times width is y and cost per feet square is for floor is $4.
02:02
Dollars.
02:03
Then we have last one which is our ceiling which is this part.
02:06
So sealing has again width and length.
02:09
So this will again be x and y times cost of sealing is three dollars.
02:14
So now this on simplification becomes three to six.
02:17
So six y z plus six x z plus four xy plus three xy.
02:26
So adding this it's become seven xy plus six x z plus six xx plus six.
02:32
X y z so this is our cost function so now we have to minimize this so we'll differentiate this with respect to we can differentiate there with x y z so there are three variables we have to convert these three variables in terms of single variable to solid so now we have volume which is x times y times z and that is given as total volume is 252 ,000 so 252 ,000 now from this we can help of this we can convert this three variable function into two variable function so let's keep x and y as a variable and replace z with xy...