2 - 1

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Section 2.4

Exponential Functions

Warm-up: Page 78 #62

How are Exponential & Logarithmic

Functions Graphed and Applied?

How are Exponential & Logarithmic Functions Graphed and Applied?

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How are Exponential & Logarithmic Functions Graphed and Applied?

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Your Turn 1

Solve

Solution: Since the bases must be the same, write 25 as 52 and

125 as 53.

/2 325 125 .x x

2 /2 3 3(5 ) (5 )x x

3 95 5 Multiply exponents. x x

3 9

Now use the property:

If 0, 1, an d , then .x ya a a a

x

x

x

y

2 9

9 / 2.

x

x

How are Exponential & Logarithmic Functions Graphed and Applied?

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Assessment Prompt #1

Page 86 #15, 17, 19

How are Functions Graphed and Applied?

How are Exponential & Logarithmic Functions Graphed and Applied?

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How are Exponential & Logarithmic Functions Graphed and Applied?

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Assessment Prompt #2

Graph

How are Functions Graphed and Applied?

How are Exponential & Logarithmic Functions Graphed and Applied?

5 2xf x e

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How are Exponential & Logarithmic Functions Graphed and Applied?

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Examples

Find the interest earned on $4400 at 3.25% interest compounded

quarterly for 5 years.

Solution: Use the formula for compound interest with P = 4400,

r = 0.0325, m = 4, and t = 5.

The investment plus the interest is $5172.97. The interest

amounts to $5172.97 − $4400 = $772.97.

1tm

rA P

m

5(4)0.0325

4400 14

A

5172.97 Use a calcula tor.

How are Exponential & Logarithmic Functions Graphed and Applied?

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Example #2

Find the amount after 4 years if $800 is invested in an account

earning 3.15% compounded continuously.

Solution: In the formula for continuous compounding,

let P = 800, t = 4 and r = 0.0315 to get

or $907.43.

rtA Pe

0.0315(4)800A e

907.43,

How are Exponential & Logarithmic Functions Graphed and Applied?

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Graphs of Basic Functions

How are Exponential & Logarithmic Functions Graphed and Applied?

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Assessment Prompt #3

How are Functions Graphed and Applied?

Group Check Page 86-87 #37,43,47

How are Exponential & Logarithmic Functions Graphed and Applied?

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HOMEWORK

pages 86-87 #14-32even,38,48

How are Functions Evaluated?How are Functions Graphed and Applied?

How are Exponential & Logarithmic Functions Graphed and Applied?