Log to the base a (z) = b (or written Log a (z) = b)
Just another way of writing a^b = z
Change of base? For example if you have log3 (7) and you want to work it out on your calculator, how can you? There's only Log (which is log to the base 10) or log to the base e (called ln) . So how can you work out a log with a base 3?
You take the log of both numbers and divide the one in brackets by the base.
So to work out log 3 (7)
= ln7 / ln3
will give you your answer on your calculator
Or same thing
= Log10 (7) / Log10 (3)
Get it....?