Let $ABC $ be an acute triangle with $\omega,S,$ and $R $ being its incircle, circumcircle, and circumradius, respectively. Circle $\omega_{A}$ is tangent internally to $S$ at $A$ and tangent externally to $\omega$. Circle $S_{A} $is tangent internally to $ S$ at $A$ and tangent internally to $\omega$. Let $P_{A}$ and $Q_{A} $denote the centers of $\omega_{A} $ and $S_{A}$, respectively. Define points $P_{B}, Q_{B}, P_{C}, Q_{C} $ analogously. Prove that
$8P_{A}Q_{A}\cdot P_{B}Q_{B}\cdot P_{C}Q_{C}\leq R^{3}\;$
Challenging Geometric Inequality: Prove $\leq R^{3}$
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Last edited by Moon on Wed Jan 05, 2011 7:58 pm, edited 1 time in total.
Reason: remember space does not work inside latex. Read the latex guide.
Reason: remember space does not work inside latex. Read the latex guide.
Re: Stamina check
whoa...man...this is not a very good problem to post here. (However, it can be a open challenge for Zubaer, Dhononjoy, Urmi, and some other guys...)
BTW you have defied a rule of the forum. You're not using a good topic.
Read: viewtopic.php?p=13&f=9#p13
BTW you have defied a rule of the forum. You're not using a good topic.
Read: viewtopic.php?p=13&f=9#p13
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.
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- Posts:20
- Joined:Thu Dec 09, 2010 3:30 pm
Re: Challenging Geometric Inequality: Prove $\leq R^{3}$
where are DJ, Urmi, ZU, Pranon, promi and others? all of you should be able to solve this
Re: Challenging Geometric Inequality: Prove $\leq R^{3}$
Yup...this is ridiculous. In our time, we did not get problems from the seniors (even after begging). Now people don't even try these problems...huh...
Oh...Tanvir vi, and Nayel vi used to give us a few problems.
Oh...Tanvir vi, and Nayel vi used to give us a few problems.
"Inspiration is needed in geometry, just as much as in poetry." -- Aleksandr Pushkin
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.
Please install LaTeX fonts in your PC for better looking equations,
learn how to write equations, and don't forget to read Forum Guide and Rules.