A company uses a truck to deliver its products. To estimate costs, the manager models gas consumption by the function

gal/mile, assuming that the truck is driven at a constant speed of x miles per hour, for x ≥ 5. The driver is paid $20 per hour to drive the truck 250 miles, and gasoline costs $4 per gallon.

a. Find an expression for the total cost C(x) of the trip.

b. At what rate is the cost C(x) changing with respect to x when the truck is driven at 40 miles per hour? Is the cost increasing or decreasing at that speed?

Transcribed Image Text:

G(x) = 1 250 1,200 X + x