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This lesson explores the basics of logarithmic functions and their applications in real-world scenarios, such as predicting population growth. It begins with the population of India in 1996, using a growth rate to derive formulas for predictions in 2000 and 2010. The session includes examples and exercises on converting between exponential and logarithmic forms, evaluating logarithms, and solving logarithmic equations. This comprehensive approach equips students with essential skills for handling logarithmic concepts in various contexts, including science and mathematics.
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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