The function y=log(a) x is often written, which means that the number x is called the logarithm based on n. Logarithm and power operations are relative. Logarithm based on 10 is often used as lg, and irrational number e is often used as ln.
Logarithm derivation formula: let b = a m and a = c n, then b = (c n) m = c (Mn) 1, and take the logarithm based on a as follows: log (a) (b) = m; 2. Take the logarithm with C as the base for ①, that is, log (c) (b) = Mn; 3，3/2，so:log(c)(b)/log(a)(b)= n = log(c)(a)∴log(a)(b)= log(c)(b)/log(c)(a)。