satisfy that: 
,![\[
\sqrt{a + b} + \sqrt{b + c} + \sqrt{c + a} \geq \frac{4(ab + bc + ca)}{\sqrt{(a + b)(b + c)(c + a)}}
\]](http://latex.artofproblemsolving.com/e/7/2/e72fd0f134289c359bc8766440babc52ae131961.png)
satisfied 
Find the minimum of 
Y by
Points 
and 
are selected on the sides 
and 
of triangle 
respectively. The segments 
and 
intersect at point 
. We know that 
. Prove that either 
or 
is cyclic quadrilateral.
(Chernyavskaya I.A., Kukina E.G.)
and 
are selected on the sides 
and 
of triangle 
respectively. The segments 
and 
intersect at point 
. We know that 
. Prove that either 
or 
is cyclic quadrilateral.(Chernyavskaya I.A., Kukina E.G.)
This post has been edited 2 times. Last edited by parmenides51, Apr 14, 2021, 4:19 AM
