logam/n=logam-logan

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logam/n=logam-loganlogam/n=logam-loganlogam/n=logam-logan1、因为n=log(a)(b),代入则a^n=b,即a^(log(a)(b))=b.2

logam/n=logam-logan
logam/n=logam-logan

logam/n=logam-logan
1、因为n=log(a)(b),代入则a^n=b,即a^(log(a)(b))=b.
2、MN=M×N   由基本性质1(换掉M和N)   a^[log(a)(MN)] = a^[log(a)(M)]×a^[log(a)(N)]   由指数的性质   a^[log(a)(MN)] = a^{[log(a)(M)] + [log(a)(N)]}   又因为指数函数是单调函数,所以   log(a)(MN) = log(a)(M) + log(a)(N)
3、与(2)类似处理 MN=M÷N   由基本性质1(换掉M和N)   a^[log(a)(M/N)] = a^[log(a)(M)]÷a^[log(a)(N)]   由指数的性质   a^[log(a)(M/N)] = a^{[log(a)(M)] - [log(a)(N)]} 又因为指数函数是单调函数,所以   log(a)(M/N) = log(a)(M) - log(a)(N)
时间比较晚了,我直接给你拉答案过来了,我就不自己打了

令x=loga(m/n)
则a^x=m/n
而a^loga(m)=m
a^loga(n)=n
所以a^x=a^loga(m)÷a^loga(n)=a^[loga(m)-loga(n)]
所以x=loga(m)-loga(n)
命题得证

a+b=1
所以y=(1/a+1/b)(a+b)
=2+(a/b+b/a)
a/b>0,b/a>0
所以a/b+b/a≥2√(a/b*b/a)=2
所以y≥2+2=4
所以最小值是4