SOLUTION: The owner of a video store has determineed the cost C, in dollars, of operating the store is approximately given by C(x)=2x^2-32x+720, where x is the number of videos rented daily.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The owner of a video store has determineed the cost C, in dollars, of operating the store is approximately given by C(x)=2x^2-32x+720, where x is the number of videos rented daily.      Log On


   

Question 512807: The owner of a video store has determineed the cost C, in dollars, of operating the store is approximately given by C(x)=2x^2-32x+720, where x is the number of videos rented daily. Find the lowest cost to the nearest dollar.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+C%28x%29+=+2x%5E2+-+32x+%2B+720+
The minimum, or lowest cost is the vertex V(x,y)
The formula for the x-coordinate is:
+-b%2F%282a%29+
when the equation is in the form
+ax%5E2+%2B+bx+%2B+c+
+a+=+2+
+b+=+-32+
+-b%2F%282a%29+=+-%28-32%29%2F%282%2A2%29+
+-b%2F%282a%29+=+32%2F4+
+-b%2F%282a%29+=+8+
Now plug this into the equation to find C%288%29+
+C%288%29+=+592+
The lowest cost is $592
You can check this by plugging +x+=+7.9+
and +x+=+8.1+ into the equation and seeing
if they are both less than +592+