Question

How do you expand `log_2 20`?

Answer 1

`2 + log 5/log 2=4.322`, nearly.

Explanation:

Use `log_b a = log_c a/log_c b, log_2 a^n=n log_2 a and log_2 2=1`

`log_2 20 = log_2((2^2)5)`

`=log_2 2^2+log_2 5`

`=2 log_2 2+log_2 5`

`= 2(1)+log 5/log 2`

#=4.322, nearly.