How do I show this inequality that \frac{\ln(x+1)}{\ln(x)}\leq \frac{x}{x−1} for x>1?

PEEWSRIGWETRYqx

PEEWSRIGWETRYqx

Answered question

2022-01-22

How do I show this inequality that
ln(x+1)ln(x)xx1 for x>1?

Answer & Explanation

esfloravaou

esfloravaou

Beginner2022-01-22Added 43 answers

You can show it using concavity of lnx as follows:
The given inequality is equivalent to
lnxx1xln(x+1)
Now, since x>1 we have
x1xln(x+1)+1xln1concavityln(x1x(x+1)+1x1)=lnx
Done
Esta Hurtado

Esta Hurtado

Beginner2022-01-23Added 39 answers

For x>1
xlnx(x1)ln(x+1)=1xtu1u(u+1)2dudt0
Rearrange the inequality to obtain
ln(x+1)lnxxx1
RizerMix

RizerMix

Expert2022-01-27Added 656 answers

(Fill in the gaps as needed. If youre

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