Consider a variable point

inside a given triangle

. Let

,

,

be the feet of the perpendiculars from the point

to the lines

,

,

, respectively. Find all points

which minimize the sum
%V0
Consider a variable point $P$ inside a given triangle $ABC$. Let $D$, $E$, $F$ be the feet of the perpendiculars from the point $P$ to the lines $BC$, $CA$, $AB$, respectively. Find all points $P$ which minimize the sum $${BC\over PD}+{CA\over PE}+{AB\over PF}.$$