How do you use the Change of Base Formula and a calculator to evaluate the logarithm log21?

2 Answers
Apr 30, 2018

I tried this:

Explanation:

Actually you do not even need to change base as:

log21=0

because: 20=1

Anyway, we can change into natural logs and write:

log21=ln1ln2=0

using our calculator.

Apr 30, 2018

log101log102=0

Explanation:

It's probably easier to study the pattern I'm putting out below than it would be to sort through my math explanation.

Change of base will always look like this:

logxy=log10ylog10x

When I learned trig earlier this year, I just memorized that formula.

As for the calculator part, calculator log(x) is always equal to log10(x), so instead of worrying about your bases of ten, just plug in:

log(1)log(2)

You should get

log(1)log(2)=0