Exponential Function Review Name ______
1) A certain type of bacteria, given the right conditions, doubles in population every 6 hours. Given that there were approximately 100 bacteria to start with, how many bacteria will there be in a day and a half?
2) The population in the town of Huntersville is presently 38,300. The town grows at an annual rate of 1.2%. What will the population be in seven years?
3) If you invest $5000 at an annual interest rate of 6.5% that is compounded quarterly, how much money will you have after 3 years?
4) A block of plutonium has a half life of 8 hours. How much of a 15 gram block will be left in 3 days?
5) $1250 is invested at 11% for 4 years. Find the interest if it is compounded monthly.
6) How long will it take to double $5000 if your bank account pays 7% interest semi-annually?
7) Jimmy needs $5000 for an in-grown pool. How much should he invest at an interest rate of 8.7% compounded daily over four years?
8) Trees are being cut down every year in Sherwood Forest. 2% of each acre is destroyed every year. If there are 700 acres in Sherwood Forest this year, how many will be present in four years?
Describe how each graph has been translated:
2. 2(.5)x-4 + 3______
3. 5(12)x+1 + 6______
4. -7(.9)x-10- 1______
5. -8(4) x+13- 4______
9) The table below gives the amount A in a savings account t years after the account was opened.
a) Find an exponential model for the data.
t / 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8A / 145 / 190 / 250 / 330 / 440 / 600 / 780 / 990 / 1320
b) Use your model to predict how much money will be in the account after 10 years.
10) Evaluate at x = 3
11) Evaluate at x = 3.
12) Evaluate at n = -2.
13) Evaluate at n = 6
Sketch the graph of each function:
14) 15)
Write an equation for the function y = 3(5)x given the following translations:
16) down 6, right 2______
17) left 3, down 4______
18) up 9, left 1.5______
19) right 8, up 2______
20) left 1, down 1______
21) A population of single-celled organisms was grown in a Petri dish over a period of 16 hours. The number of organisms at a given time is recorded in the table below.
a. Find an exponential model for the data. ______
b. Using the model you found in part a, predict how many organisms will exist after 25 hours.