1.1:00
2.2:30
3.4:45
4.3:15
5.11:45
6.6:15
7.6:00
8.2:30
9.6:45
10.6:55
11.4:45
12.10:15
Question number 2
1.7:30
2.10:30
3.3:30
4.5:30
5.9:30
6.12:30
Answer:
?
Step-by-step explanation:
Answer:
P is exactly 3km east from the oil refinery.
Step-by-step explanation:
Let's d be the distance in km from the oil refinery to point P. So the horizontal distance from P to the storage is 3 - d and the vertical distance is 2. Hence the diagonal distance is:

So the cost of laying pipe under water with this distance is

And the cost of laying pipe over land from the refinery to point P is 400000d. Hence the total cost:

We can find the minimum value of this by taking the 1st derivative and set it to 0

We can move the first term over to the right hand side and divide both sides by 400000


From here we can square up both sides






d = 3
So the cost of pipeline is minimum when P is exactly 3km east from the oil refinery.