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

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

(2)log(a)(M/N)=log(a)(M)-log(a)(N)

(3)log(a)(M^n)=nlog(a)(M) (n∈R)

(4)log(a^n)(M)=(1/n)log(a)(M)(n∈R)

(5)log(a)(MN)=log(a)(M)+log(a)(N)

(6)a^(log(b)n)=n^(log(b)a)