log(a^n)M=1/nlog(a)(M) 怎么证明?

问题描述:

log(a^n)M=1/nlog(a)(M) 怎么证明?

用换底公式证明.
证:设c>0,且c≠1,则:
log(a^n)M=log(c)M /log(c)(a^n)=log(c)M /[n*log(c)a]=1/n*[log(c)M/log(c)a]=1/nlog(a)M
所以命题得证.