oktw says to #ysitd <licson>: 1. log(xy) = log(x) + log(y) 2. log(x/y) = log(x) - log(y) 3. log(x ^ y) = y log x 4. log(x ^ (1/p)) = log x / p 5. log_a(x) = log(x) / log(a)