8.6.notebook
April 07, 2015
ACT Prep
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8.6.notebook
April 07, 2015
8.6 Natural Logarithms
natural logarithms: y = logex
• written as y = lnx
• inverse of y = ex
**Properties of common logarithms apply to natural logarithms**
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8.6.notebook
April 07, 2015
Write as a single natural logarithm
3ln6 ­ ln 8
3lnx + lny
1/4ln3 + 1/4lnx
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8.6.notebook
April 07, 2015
Solve natural logarithm equations
ln(3x ­ 9) = 21
ln(3x + 5)2 = 4
**ONLY difference from last week's problems??
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8.6.notebook
April 07, 2015
Solve exponential equations
e2x/5 + 7.2 = 9.1
7e2x + 2.5 = 20
An initial investment of $100 is now valued at $149.18. The interest rate is 8%, compounded continuously. How long has the money been invested?
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8.6.notebook
April 07, 2015
Homework
p 464: 1­9, 14­30
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