Skip to content
← All questions

How to simplify ln⁡2n−ln⁡n\ln 2n - \ln n using logarithmic properties?

Use the quotient rule for logarithms, which states that ln⁡a−ln⁡b=ln⁡(ab)\ln a - \ln b = \ln \left(\frac{a}{b}\right). Applying this to ln⁡2n−ln⁡n\ln 2n - \ln n gives ln⁡(2nn)\ln \left(\frac{2n}{n}\right), which simplifies to ln⁡2\ln 2 since 2nn=2\frac{2n}{n} = 2.

Conditions

  • a>0a > 0 and b>0b > 0 (here 2n>02n > 0 and n>0n > 0).
  • The base of the logarithm is ee (natural logarithm).

Reasoning, step by step

  1. Identify the expression as a difference of two logarithms with the same base.
  2. Apply the quotient rule: ln⁡2n−ln⁡n=ln⁡(2nn)\ln 2n - \ln n = \ln \left(\frac{2n}{n}\right).
  3. Simplify the fraction inside the logarithm: 2nn=2\frac{2n}{n} = 2.
  4. Conclude that the expression equals ln⁡2\ln 2.

Example

The video states: 'we can handle these first two terms using this logarithmic property'. The screen shows ln⁡2n−ln⁡n\ln 2n - \ln n being simplified to ln⁡2nn\ln \frac{2n}{n} and then to ln⁡2\ln 2.

Common misconceptions

  • Confusing the quotient rule with the product rule (ln⁡a+ln⁡b=ln⁡(ab)\ln a + \ln b = \ln(ab)).
  • Incorrectly simplifying 2nn\frac{2n}{n} to 2n2n or nn.

Watch the explanation

Explore next

Answers are generated from source material and independently checked. Consult the original video or creator if something is unclear.