1. Exponential Functions You start a new job at age 22. If you invest $125 in a retirement plan each month, your company will invest another $125. The investment plan earns an annual rate of return of 8%. How much money will you have when you retire at age 65? a.$ 64,500 b.$ 129,000 c.$ 258,000 d.$1,119,000

2. Precalculus Section 5.1 Simplify exponential expressions Solve exponential growth and decay problems Recall: An exponential expression takes the form: b x where b is the base and x is the exponent. Simplify http://www.brightstorm.com/math/algebra/exponents/introduction- to-exponents/ Simplify -4 2 Simplify (-4) 2 http://www.mathvids.com/lesson/mathhelp/72- laws-of-exponents-review http://www.mathvids.com/lesson/mathhelp/72- laws-of-exponents-review

3. Laws of exponents 1.∙ ∙ = 2. = 3.If b≠ 0,1,-1 then =, iff x = y 4.(ab) x = a x b x 5. = 6. = 7. b -x = (5a 3 )(4a 2 ) (2x) 5

4. Simplify (5x 3 y 2 )(6x 4 y 8 ) 20a 7 b 2 5a 4 b 8 (2x 3 y) 3 12a 7 b -3 3a -1 b 5 (4 -2 + 2 -3 ) -1

5. The cost of college tuition has been increasing at a rate of 8% per year. If the cost of tuition is now $2000, what will it be in 12 years? time0123t12 cost2000

6. Exponential growth/decay formula A(t) = A 0 (1+r) t A(t) = amount at time t A 0 = initial amount r = growth/decay rate t = time The cost of firewood has been increasing at a rate of 6% per year. What will a $120 cord of wood cost in 9 years?

7. A radioactive isotope decays so that the radioactivity decreases by 15% per day. If 40 kg are present now, how much will be present in 6 days from now?

8. assignment Page 173 Problems 2-32 even, 33-36 all, 38,42,44,45ec