lnx+ lny=lnxy

lnx-lny=ln(x/y)

lnxⁿ=nlnx

ln(ⁿ√x)=lnx/n

lne=1

ln1=0 对数函数的运算法则公式:

1、a^log(a)(b)=b   

2、log(a)(a)=1   

3、log(a)(mn)=log(a)(m)+log(a)(n);   

4、log(a)(m÷n)=log(a)(m)-log(a)(n);   

5、log(a)(m^n)=nlog(a)(m)   

6、log(a)[m^(1/n)]=log(a)(m)/n