Multiplying logarithms by a constant
When raising a logarithm to a power, you can bring the power out in front as a multiplier:
Example: Evaluate \log_2(32^3)
- Bring the power of 3 to the front:
3 \times \log_2(32) . \log_2(32)=5 because2^5=32 .- So,
3 \times \log_2(32) = 3 \times 5 = 15 . - Answer:
15 .
Example: Evaluate \log_{10}(1000^4)
- Bring the power of 4 to the front:
4 \times \log_{10}(1000) . \log_{10}(1000)=3 because10^3=1000 .- So,
4 \times \log_{10}(1000) = 4 \times 3 = 12 . - Answer:
12 .
Splitting up a logarithm with a multiplier
You can also split up a logarithm with a multiplier into a logarithm with an exponent:
Example: Write 4 \times \log_3(9) as a single logarithm
- The power will become 4:
\log_3(9^4) . 9^4 = 6561 .- So,
4 \times \log_3(9) = \log_3(6561) . - Answer:
\log_3(6561) .
flashcards
| Question | Answer |
|---|---|
| What is the rule for bringing a power out in front of a logarithm? | |
| How do you evaluate | Bring the power 3 to the front: |
| How do you evaluate | Bring the power 4 to the front: |
| How do you rewrite a logarithm with a multiplier (e.g., | |
| How do you write | The power becomes 4: |