Solve equations using logarithms and exponentials

1
Unit 2

• Solve equations using logarithms and exponentials

2
Solving Exponential Equations

• You can use logs to solve exponential equations,
  start by writing in log form.

3
Solving Natural Logs

• Define Natural Logarithm a logarithm with base
  e
• You solve natural logs the same way as any other
  log.
• SOLVE

4
Solving Log Equations
If you dont see the base its base 10

• You can use exponential equations to solve logs
• To solve a log equation first write as one log
  (if possible), then write in expo. form to solve.

5
How could you use Logs in the Real-World?

• Your lumber company has 1,200,000 trees. You plan
  to harvest 7 of the trees each year. How many
  years will it take to harvest half of the trees?

After about 9 years and 6 months you will have
harvested half of the trees.
6
Solving Exponential Equations

• You can use calc. to help solve exponential
  equations
• Set equal to zero
• Graph and find where it crosses the x-axis

Hint also graph y0 and find where the two
lines intersect.
7
practice

• Pg 473 15-25 odd 32-35 40-43
• Pg 473 1-4, 7-12, 36-39, 49