Tattoo this on your wrist:
if a^p = x then p = LOG(x) / LOG(a)
Right, I should know the answer and I'm ashamed to have to ask for help but this is doing my head in.
Actually trying to use this formula for a spreadsheet but I'm totally flumoxed!
So, if A^X = B/C, how do I work out what X is?
E.g, I know that 1.5^14 = 4379/15, but what if I didn't know that X was 14, how can I work it out?