Exponential and Logarithmic Functions

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Chapter 8 Exponential and Logarithmic Functions
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Exponential Growth and Decay
Exponential Function y abx This function is
Exponential Growth if agt0 and bgt1. Ex y ½
(3)x It is Exponential Decay if agt0 and
0ltblt1. Ex y 5( ½ )x
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State whether f(x) is an exponential growth or
decay
Decay
f(x) 5(2/3)x
Growth
f(x) 8(3/2)x
Growth
f(x) 10(3)-x
f(x) 10(1/3)x
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Exponential graphs
Basic graph of y 2x
Exponential Growth
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Exponential graphs
Basic graph of y (½)x
Exponential Decay
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Compound Interest
A P(1 r/n)nt Where A is the amount in the
account after interest P is the initial amount
invested r is the interest rate converted from
to decimal n is the number of times compounded
per year t is the number of years
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You deposit 1000 in an account that pays 8
annual interest. Find the balance after 1 year if
the interest is compounded with the given
frequency. a. annually b. quarterly c. daily

• Annually
• A 1000(1.08/1)11
• A 1000(1.08)
• A 1080

b. Quarterly A 1000(1.08/4)41 A
1000(1.02)4 A 1082.43
c. Daily A 1000(1.08/365)3651 A
1000(1.000219178)365 A 1083.28