graphing calculator

I dont have a graphing calc in front of me but for reason if i remember correctly you cant do logs of anything other than base 10 on the calculator unless you do it the manual way.

There is a way around.
Using one of four fundamental properties of Log

lob x (base b) = log x (base a) / log b (base a)

So

log x (base 3) = log x (base 10) / log 3 (base 10 )


Hope it helps