How do you use the Change of Base Formula and a calculator to evaluate the logarithm #log_2 6 +log_3 5#?

1 Answer
Nov 3, 2015

I found #~~4.05#

Explanation:

The Change of Base Formula allows you to change the base of your log to a more "friendly" base such as #e# or #10# that can be evaluated using a pocket calculator:
#log_bx=log_cx/log_cb# from base #b# to #c#;
In our case we can use, say, #e# as new base to get Natural Logs as:
#log_2(6)+log_3(5)=ln6/ln2+ln5/ln3=#
using a pocket calculator you get:
#=1.79175/0.69314+1.60943/1.09861~~4.05#