A cable company is asked to provide service to a customer whose house is located 2 miles from the road along which the cable is buried. The nearest connection box for the cable is located 5 miles down the road. Installation cost is 2.1 cents per foot along the road and 3.5 cents per foot off the road. Describe at what point the cable installation turns off the road AND what the minimum cost for the installation will be.
2007-09-22 05:11:57 · 4 answers · asked by Hamza 1 in Science & Mathematics ➔ Mathematics
C = 5280[2.1(5-x) + 3.5(sqrt(x^2+4)]
dC/dx = -5280*2.1 +5280*7x/sqrt(x^2+4)
Set above to 0 getting:
-2.1 = -7x
x = .3
So C = 5280[2.1(4.7) +3.5(2.022)] = $894.80
2007-09-22 05:42:55 · answer #1 · answered by ironduke8159 7 · 0⤊ 0⤋
From the box to the turn is 5 miles, so 5 X 5280 X 2.1 cents. From the road to the house is 2 X 5280 X 3.5 cents. The point that the cable install turns off the road is 5 miles from the box. So from the box to the turn off is $554.40 and from the turn to the house is $369.30. Total install cost is $923.70. And that's why there is Dish Network.
2007-09-22 12:30:26 · answer #2 · answered by skwonripken 6 · 0⤊ 0⤋
Well there is 5,280 feet in a mile. And I think it will be 2.1 cents for the 5 mile distance and 3.5 cents for the 2 mile distance. So the Answer would be $554.40 for the 5 miles and $369.60 for the 2 miles. Total cost would be $924. Hope that is right for you!!
2007-09-22 12:27:25 · answer #3 · answered by pmasso83 1 · 0⤊ 0⤋
Pythagoras theorem. Find the hypotenuse.
2007-09-22 12:22:24 · answer #4 · answered by ag_iitkgp 7 · 0⤊ 0⤋