对数的性质

1、对数基本性质：a^(log(a)(b))=b；log(a)(a^b)=b；log(a)(MN)=log(a)(M)+log(a)(N)；log(a)(M÷N)=log(a)(M)-log(a)(N)；log(a)(M^n)=nlog(a)(M)；log(a^n)M=1/nlog(a)(M)。2、其他性质：换底公式：log(a)(N)=log(b)(N)÷log(b)(a)；log(a)(b)=1/log(b)(a)；对数函数的图象都过(1,0)点。