Algebra Chapter 7 Notes

Exponents and Exponential Functions

7.1 Apply Exponent Properties Involving Products

Order of magnitude: ______

______

Power: ______

Exponent: ______

Base: ______

Product of Powers Property: ______

Simplify the expressions:

a.26∙ 28b.(–3)7 ∙ (–3)

  1. (–7)3 ∙ (–7) ∙ (–7)4d. m ∙ m5 ∙ m6

Power of a Power Property: ______

Simplify the expressions:

a.(33)6 b.[(–12)7]6

c.(d5)2d.[(x – 3)3]4

Power of a Product Property: ______

Simplify the expressions:

a.(16 ∙ 21)4b.(6mn) 3

c.(–5p) 3d.–(2q)4

Use all three properties

Simplify (–3y5)3 • 2y2.Simplify • d

7.2 Applying Exponent Properties Involving Quotients

Quotient of Powers Property: ______

Simplify the expressions.

a. b.

c. d.

Power of a Quotient Property: ______

Simplify the expressions.

a. b.

Use the properties of exponents: Simplify the expressions.

a. b.

Solve a real world problem:Distances The distance from Earth to the nearest galaxy is about 1022 meters. The distance from Earth to the North Star is about 1019 meters. How many times further from Earth is the nearest galaxy than the North Star?

7.3 Define and Use Zero and Negative Exponents

Zero exponents: ______

Evaluate the expressions.

a.150b.c. (-6)0

Negative exponents: ______

Evaluate the expressions.

a.4–3 b.

c. (–5)–4d.

Evaluate exponential expressions.

a. 1316 • 13–14b. [(–2)–4]2

c.(–4)7 • (–4)–9d.

Use properties of exponents: Simplify the expression. Write your answer using only positiveexponents.

a.(3m–2n)3 b. (5x2y–3z)4

c. d.

Remembering the exponent properties:

Zero Exponent
Negative Exponent
Product of Powers
Quotient of Powers
Power of a Power
Power of a Product
Power of a Quotient

7.4 Write and Graph Exponential Growth Functions

Exponentialfunction: ______

Exponential growth: ______

Compound interest: ______

Example 1: Write a rule for the function.

Example 2: Graph the function y = 5 • 3x. Identify its domain and range.

x / –2 / –1 / 0 / 1 / 2
y

EXAMPLE 3: Graph y = –• 4x and y = 2 • 4x. Compare each graph with the graph of y = 4x

x / y = 4x / y =•4x / y = 2•4x
–2
–1
0
1
2

Exponential Growth Model: ______

Example 4: The owner of an original copy of a 1938 comic book sold it at an auction in 2005 The owner bought the comic book for $55 in 1980. The value of the comic book increased at a rate of 2.8% per year.

a. Write the function that models the value of the comic book over time.

b. What was the approximate value of the comic book at the time of the auction in 2005? Round your answer to the nearest dollar.

Example 5: You put $125 in a savings account that earns 2% interest compounded yearly. You do not make any deposits or withdrawals. How much will your investment be worth in 5 years?

7.5 Write and Graph Exponential Decay Functions

Exponential decay: ______

Example 1: Tell whether the table represents an exponential function. If so, write a rule for the function.

x / –1 / 0 / 1 / 2
y / / –2 / –12 / –72

Example 2:Graph the function y = . Identify its domain and range.

x / –1 / 0 / 1 / 2
y

Example 3: Tell whether the graph represents exponential growth or exponential decay. Then write a rule for the function.

a.b.

Exponential Decay Model: ______

Example 5: A farmer bought a tractor in 1999 for $30,000. The value of the tractor has been decreasing at a rate of 18% per year.

a. Write a function that models the value of the tractor over time.

b. What was the approximate value of the tractor in 2005?