Hello..

I need help to prove this inequalities (Worried)

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- Sep 2nd 2011, 03:07 AMMhmh96need help to prove inequalities
Hello..

I need help to prove this inequalities (Worried)

http://a7.sphotos.ak.fbcdn.net/hphot..._6695647_n.jpg - Sep 4th 2011, 12:50 PMArythRe: need help to prove inequalities
I don't know how good you are at inequalities but it basically goes like this:

$\displaystyle \frac{a}{b} + \frac{b}{c} + \frac{c}{d} + \frac{d}{a} = $ $\displaystyle \frac{a^2cd}{abcd} + \frac{b^2ad}{abcd} + \frac{c^2ab}{abcd} + \frac{d^2bc}{abcd}$

$\displaystyle = \frac{a^2cd + b^2ad + c^2ab + d^2bc}{abcd} \leq \frac{a^2 + b^2 + c^2 + d^2}{abcd}$ $\displaystyle \leq \frac{a + b + c + d}{abcd} \leq \frac{4}{abcd}$

So, $\displaystyle \frac{a}{b} + \frac{b}{c} + \frac{c}{d} + \frac{d}{a} \leq \frac{4}{abcd}$ - Sep 4th 2011, 12:55 PMalexmahoneRe: need help to prove inequalities