How do you use the Change of Base Formula and a calculator to evaluate the logarithm #log_8 77#? Precalculus Properties of Logarithmic Functions Functions with Base b 1 Answer Alan N. Jun 12, 2018 #log_8 77 approx 2.08893# Explanation: #log_a b = ln b/ln a# #:. log_8 77 = ln 77/ln 8# #approx 4.34381/2.079442# #approx 2.08893# Check: #8^2.08893 approx 77.00# Answer link Related questions What is the exponential form of #log_b 35=3#? What is the product rule of logarithms? What is the quotient rule of logarithms? What is the exponent rule of logarithms? What is #log_b 1#? What are some identity rules for logarithms? What is #log_b b^x#? What is the reciprocal of #log_b a#? What does a logarithmic function look like? How do I graph logarithmic functions on a TI-84? See all questions in Functions with Base b Impact of this question 3759 views around the world You can reuse this answer Creative Commons License