问题标题:
设x,y,z属于(0,正无穷大)且3^x=4^y=6^z求证1/X+1/2^Y=1/Z
问题描述:
设x,y,z属于(0,正无穷大)且3^x=4^y=6^z求证1/X+1/2^Y=1/Z
冯小林回答:
证明
设3^x=4^y=6^z=k
则x=log3(k)=1/logk(3)
y=log4(k)=1/logk(4)
z=log6(k)=1/logk(6)
则1/x+1/(2y)=logk(3)+logk(4)/2
=logk(3)+logk(2)
=logk(6)=1/z
证毕
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