对数函数比较大小

log（1/2）5和log（5）0.1怎么比较大小呢？试了试倒数还是不会

全部回答

2008-02-25

0 0

x =log(1/2)5 = log(5)/log(1/2) y = log(5)0。1 = log(1/10)/log(5) x - y = log(5)/log(1/2) - log(1/10)/log(5) = (log(5)*log(5) -log(1/10)*log(1/2))/(log(5)*log(1/2)) =(log(5)*log(5)-(-log(10))*(-log(2)))/(log(5)*(-log(2))) =(log^2(5)-log^2(2)-log(5)*log(2))/(-log(5)*log(2)) =-(log(5)*log(5/2)-log(2)*log(2))/(log(5)*log(2)) <0; x < y; log(1/2)5 < log(5)0。
1。

提交