How do you use the Change of Base Formula and a calculator to evaluate the logarithm #log_3 73#?

1 Answer
Jul 9, 2015

Answer:

#log_3 73~~3.095#

Explanation:

The Change of Base Formula says that:

#log_a x=log_b x/log_b a#

Calculators don't have #log_3 x# button, but they have "log" which is base 10 logarythm and "ln" which is natural logarythm (base #e#), so you can use this formula in such a way (using base 10 log):

1) Calculate #log 3#
2) Put the result in memory (button "X->M" or simmilar)
3) Calculate #log 73#
4) Press divide button
5) Recall memory result (button "RM" or simmilar)
6) Press result (=) button.

Note: Using "ln" instead of "log" is also possible.