Evaluating Logarithms

Use Evaluate or Evaluate Numerically for numerical approximations. Note that Evaluate converts to natural logarithms symbolically, and use of floating-point notation triggers a numerical evaluation. Change the Settings dialog box for the degree of accuracy you need. In these examples, Digits Used in Display is set to 5.

Expression Evaluate Evaluate Numerically
ln 2 ln 2  .69315
log105  ${\frac{{\ln 5}}{{\ln 2+\ln 5}}}$   .69897
ln 0.0025   - 5.9915 -5.9915
ln 1.0025 2.4969×10-3 2.4969×10-3