Calculus: Early Transcendentals, Chapter 1, 1.6, Section 1.6, Problem 40

Use the Properties of Logarithm to evaluate each logarithm correct to six decimal places.
a.) $\log_{12} 10$
b.) $\log_{2} 8.4$


a.) $\displaystyle \log_{12}10 = \frac{\ln 10}{\ln 12} = 0.926628$
b.) $\displaystyle \log_{2} 8.4 = \frac{\ln 8.4}{\ln 2} = 3.070489$