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Warm-Up: February 1, 2013. The population of India was 952,108,100 in 1996 and was growing at a rate of 1.3% per year. Write the expression that would predict the population in 2000. Write the expression that would predict the population in 2010. Homework Questions?. Logarithmic Functions.
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Warm-Up: February 1, 2013 • The population of India was 952,108,100 in 1996 and was growing at a rate of 1.3% per year. • Write the expression that would predict the population in 2000. • Write the expression that would predict the population in 2010
Logarithmic Functions Section 6.3 Part 1
Essential Questions • How can we convert between logarithmic and exponential forms?
Logarithm • The logarithm of a number to a certain base is the exponent to which the base must be raised to equal the number.
Example 1 • Evaluate each of the following logarithms: • A) log525 • B) log28 • C) log381
You-Try #1 • Evaluate each of the following logarithms
Use of Logarithms (don’t copy) • pH scale in chemistry • Decibels – noise levels • Richter scale – earthquake strength • Apparent magnitude (brightness) of a star • Musical intervals – semitones
Converting Forms Exponential form Logarithmic form 103 = 10003 = log101000 Exponent Base Move the base to the other side of the equation
Converting Forms • You can take the log (with same base) of both sides • Or you can make both sides exponents with the same base. • Logs and exponents of the same base “cancel”
Example 2 • Convert to Logarithmic form
You-Try #2 • Convert to Logarithmic form
Example 3 • Convert to Exponential Form
You-Try #3 • Convert to Exponential Form
Evaluating Logarithms • To evaluate a logbx, ask yourself, “b to what exponent gives me x?”
Example 4: Solve • Solve v=log100.001
You-Try #4: Solve • Solve v=log41
Assignment • Page 374 #12-35, 56-67
Warm-Up: February 4, 2013 • Evaluate the following logarithms
Logarithmic Functions Section 6.3 Part 2
Essential Question • How can we solve logarithmic equations?
Solving for y • Evaluate the logarithm • We did this last class
Solving for b • Convert to exponential form • Use a radical or fractional exponent to isolate b • Remember b>0
Solving for x • Convert to exponential form • Evaluate the exponential
Assignment • Page 375 #68-85