1. Warmup 4-25 List transformations and analyze the following
exponential function:
Transformations:
Domain: Range:
Asymptote: Growth or Decay:
2. Simplify:
Simplify:
Simplify :
7. Solve for x:

2. Compound Interest Formula A = P(1+(r/n))nt A = Amount earned P = Principle(amount Put in) r = interest rate n = number of times compounded PER YEAR t = time in YEARS To enter compound interest in calculator, type: P((1 + (r%/n))(n*t) , enter (If calculator has no % button, divide r by100,put this decimal in for r in formula)

3. Notes – Compound Interest EXAMPLES
Ex: John wants to invest $2000 at 4.25% for 3 years.
How much would John end up with at the end of the 3 years if
the interest was compounded monthly?
Ex: What if the interest in the example above were compounded
quarterly? How much would John have at the end of the 3 years?
Ex Just before he decides on which investment to make, John
finds a different offer. He can only get 4%, but the interest is
compounded daily. How much would John have at the end of
3 years with this option?
Ex: Meg wants to invest $18500 at 5.375% for 5 years.
How much would Meg end up with at the end of the 5 years if
the interest was compounded:
a. Annually?
b. Weekly?
c. Semi-Annually?
d. Daily?

4. Exponential Word Problems Practice
For the following problems, use the formula: A = P r nt or A = Pert n
If Jon has $8500 to invest for 5 years and the bank will
offer a CD at 3.25%, how much would he have if the money
were compounded:
1. Annually?
2. Daily?
3. Weekly?
Monthly?
Semi-Annually?
Nicole has saved up $9600 towards going to college. She wants to invest it
in an account that yields 4.5% interest for 4 years. How much money will she
have at the end of the 4 years if the interest in compounded:
6. Weekly?
7. Daily?
8. Monthly?
9. Annually?
Quarterly?
Nick has been given $5400 to invest towards buying his first car. The bank offers an account that yields 3.75% interest for 3 years. How much money
will Nick earn if the interest is compounded:
11. Quarterly?
12. Monthly?
13. Daily?
Weekly?

5. Ticket out the Door 4-22 Compound Interest
If Pam has $3500 to invest for 5 years and the bank will offer a CD at 2.75%, how much would she have if the money were compounded:
Weekly?
Quarterly?
Semi-Annually?
Monthly?
Daily?

6. Compound Interest Part 2 (CONTINUOUSLY COMPOUNDED INTEREST) New Formula: A = Pert A = Amount Earned P = Principle(amount INVESTED) r = Interest rate t = time in years To enter this formula into calculator: P, 2nd ln(for e),(r*t) IMPORTANT: If the word “invests”is in problem,use normal formula. If the word “needs” is in problem, use the formula, P = A ert

7. Notes – Compound Interest Formula Pert EXAMPLES
Ex. Suppose a person had $3600 to invest at 3.5% for 6 years. How
much would they have at the end of the 6 years if the interest were
compounded continuously?
Ex. Mary won $7500 in a lottery game. She wants to invest it in an
account that earns 5.75% for 4 years. If the interest is compounded
continuously, how much would Mary have in the account after 4
years?
Ex. Jamie has inherited $9000 from her grandparents. She wants
to invest the money in an account earning % interest for
4 years. If the interest is compounded continuously, how much money
will Jamie have in the account after 4 years?
Pert formula part 2 Examples
Ex. Janice needs to earn $10000 in 8 years from her investments.
How much money would she need to invest to make this much at
4.25% interest? (interest is compounded continuously)
Ex. How much would Janice need to invest in the account above
if she could wait 12 years?
Ex. Jack needs to earn $4800 to put towards the purchase of a car.
If he can get an account that earns 5.5% interest compounded
continuously, how much does he need to invest for:
4 years?
7years?
10 years?

8. Exponential Word Problem Practice Part 2
1. Tim has $4500 to invest. He can get an account that earns 4.75%
interest compounded continuously for 5 years. How much money will
be in his account at the end of the 5 years?
2. Terri has $9400 to invest. She can get an account that earns 3.5%
interest compounded continuously for 3 years. How much money will
be in her account after 3 years?
Steve won $15000 in the lottery. He wants to invest it in an account
that earns 2.875% interest for 6 years. If the interest is compounded
continuously, how much money will he have after 6 years?
Amanda won $3200 in a radio contest. She wants to invest the money in an account earning 3.25% interest for 8 years. If the
interest is compounded continuously, how much would she have in
her account after 8 years?
Jesse has saved $1800 from his last several birthdays. He would like
to invest the money in an account that earns 5.375% interest for 7 years.
If the interest is compounded continuously, how much money will Jesse
have at the end of the 7 years?
Jessica has earned $24800 from the sales of her books. She wants
to invest the money in an account that earns 3.5% interest for 10 years.
If the interest compounds continuously, how much will Jessica have in
her account after 10 years?

9. Exponential Word Problem Practice Part 2
7. Kaitlyn has $2900 in credit card debt. Her credit card charges
11.75% interest, compounded continuously. How much will she owe
on the balance if she does not make a payment for:
a. 9 months? b. 2 years? c. 4 years?
8. Justin has $4200 in credit card debt. His card has an interest rate
of 12.25% compounded continuously. How much would he owe if he
didn’t pay on the balance for:
a. 6 months? b. 1year? c. 3 years?
Jane needs to make $6300 to help pay for a car. She is investing
some money in an account that earns 4.125% interest that is compounded continuously. How much money must she invest if she
is willing to wait:
a years? b. 5 years?
Kristen needs $2900 to pay for a computer. She is investing some
money she has saved in an account that earns 3.875% compounded
continuously. How much does she need to invest if she can wait:
a. 2 years? b. 6 years?
Jeremy needs $4200 to help put down money on a house. He is
investing some money in an account that earns 5.25% interest,
compounded continuously. How much does he need to invest to reach
his goal if he can wait:
a. 4 years? b. 8 years?
12. Andrea needs $10000 to help pay off some debts. She is investing
some money in an account that earns 3.125% interest, compounded
continuously. How much would she need to invest to reach this goal if
she can wait: a. 5 years? b. 10 years?

10. Ticket out the door 4-25 Exponential word problems part 2
1. Mark has $2400 to invest. He can get an account for 5 years that earns 3.875% interest, compounded continuously. How much would he earn at the end of the 5 years?
Michelle has $7200 she wants to invest. She can get an account earning 3.125% interest for 4 years. If the interest is compounded continuously, how much would Maggie have in her account at the end of the 4 years?
Jeremy needs $7500 to put down on a car. If he can get an account earning 3.75% interest compounded continuously, how much would he need to invest if he could wait 3 years?
Peg needs to make $5400 to put towards a down
payment on a house. If she can get an account earning 5.25% interest compounded continuously, how much would she need to invest if she can wait 5 years?