Suppose that the speed of a car, measured in miles per hour (mph), is monitored for some short
period of time after the driver applies the brakes. The following table and graph relate the speed of
the car to the amount of time, measured in seconds (sec), elapsed from the moment that the brakes
are applied. What is happening to the speed of the car during this time frame? In which of the time
intervals does the speed change the most?
TIME
(seconds)
SPEED
(mph)
249
434
624
814
10 9
With increasing elapsed time, the speed increases. The speed changes most during the time
interval from 2 seconds to 4 seconds.
With increasing elapsed time, the speed decreases. The speed changes most during the time
interval from 8 seconds to 10 seconds.
With increasing elapsed time, the speed decreases. The speed changes most during the time
interval from 2 seconds to 4 seconds.
With increasing elapsed time, the speed increases. The speed changes most during the time
interval from 8 seconds to 10 seconds.
A cable TV company charges $25 for the basic service plus $7 for each movie channel. Let y be the
total cost in dollars of subscribing to cable TV, using x movie channels. Find the slope–intercept
form of the equation.
Graph the equation by using the slope and y–intercept.