Question

Brenda and her husband are traveling through the hill country. Brenda is using a GPS device to record her altitude over the course of her trip. After beginning the trip driving uphill, at 7 minutes into the drive she notices that they are at sea level. At sea level, altitude readings read 0: above sea level makes altitude readings positive, and below sea level makes altitude readings negative. After 7 minutes the altitude readings became positive and stayed positive until 9 minutes into the drive. Nine minutes into the drive they are again at sea level, for the last time during the trip, and afterwards continue to be above sea level.

a. If a function was created to model their altitude over the course of the trip, how many zeros would it have? Why?

b. For each zero, determine if the graph of the function would cross or only touch the x-axis based on the given information. Explain your answer.

c. Create a function, a(x), to represent their altitude after x minutes of driving using the information you have been given above.

d. After the first two minutes of driving, Brenda recorded their altitude as 23 feet below sea level. To get a better estimate of the function, use the value to determine a constant factor of the function.

e. Use the resulting equation from part d. to approximate their altitude 15 minutes after they left.

Answer 1