7.1 Exponential Models

Honors Algebra II

xy 2Exponential Growth: Graph

xaby Exponential Function: x is a real number

a ≠ 0

b > 0

b ≠ 1

Examples:

x

x

x

xf

y

y

9)(

)7(25.0

)3(2

Exponential Growthxaby b >

1

y-intercept:

Domain:

Range:

Asymptote:

Exponential Decayxaby 0 < b <

1

y-intercept:

Domain:

Range:

Asymptote:

xy 32Graph

b> 1 is growth factor

0 < b < 1 decay factor

b = 1 + r

r is rate of increase or decrease

You invested $1000 in a savings account at the end of 6th grade. The account pays 5% annual interest. How much money will be in the account after six years?

Suppose you invest $1000 in a savings account that pays 5% annual interest. If you make no additional deposits or withdrawals, how many years will it take for the account to grow to at least $1500?

Writing Equations

Example 7: Writing Equations

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