400
Write a formula for the price p o a gallon of gas in t days if the price is $2.50 on day t=0 and the price is:
a. Increasing by $0.03 per day
b. Decreasing by $0.07 per day
c. Increasing by 2% per day
d. Decreasing by 4% per day
a. Since the rate of change is constant, the formula is the linear function p = 2.50 + 0.03t.
b. Since the rate of change is constant, the formula is the linear function p = 2.50 − 0.07t.
c. Since the percent rate of change is constant, the formula is the exponential function
p = 2.50(1.02)t .
d. Since the percent rate of change is constant, the formula is the exponential function
p = 2.50(0.96)t .