How do you use the Change of Base Formula and a calculator to evaluate the logarithm #log_4 72#?

1 Answer
Sep 24, 2015

I found: #3.0849#

Explanation:

The Change of Base Formula allows you to write:

#log_ab=(log_cb)/(log_ca)#
and change your base from #a# to the new base #c#.

We can choose, as new base, #e# and use natural logs, #ln#, that can be evaluated using a pocket calculator and get:

#log_4(72)=(ln72)/(ln4)=3.0849#