Practice Natural Logarithm in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

The logarithm with base e \approx 2.71828: \ln x = \log_e x. It is the inverse function of e^x.

If e^x asks 'what do I get after growing continuously for time x?', then \ln x asks 'how long do I need to grow continuously to reach x?' The natural log measures time in the world of continuous growth.

Example 1

easy
Evaluate \ln(e^5).

Example 2

medium
Simplify \ln(x^3) - 2\ln(x) + \ln(e).

Example 3

medium
Solve \ln(2x + 1) = 3 for x.

Example 4

hard
Find the derivative of f(x) = \ln(x^2 + 1) and determine where f is increasing.