Question

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

Answer 1

Refer to explanation

Explanation:

Using the change of base of formula

#log_(4)72=log72/log4=log(9*8)/log(2^2)=(2*log3+3*log2)/(2*log2)= 3/2+log3/log2#

Now using a calculator we see that `log2=0.69` and `log3=1.10`

so finally `log_4 72=3.08`