(1)log(a)(MN)=log(a)(M)+log(a)(N);

(2)log(a)(M/N)=log(a)(M)-log(a)(N);垍

(3)log(a)(M^n)=nlog(a)(M)(n∈R)

(4)log(a^n)(M)=1/nlog(a)(M)(n∈R)垍

5)换底公式:log(A)M=log(b)M/log(b)A(b>0且b≠1)

(6)log(a^n)M^m=(m/n)log(a)M

(7)对数恒等式:a^log(a)N=N;log(a)a^b=b