IMO Shortlist 1988 problem 13


Kvaliteta:
  Avg: 0,0
Težina:
  Avg: 0,0
Dodao/la: arhiva
2. travnja 2012.
LaTeX PDF
In a right-angled triangle ABC let AD be the altitude drawn to the hypotenuse and let the straight line joining the incentres of the triangles ABD, ACD intersect the sides AB, AC at the points K,L respectively. If E and E_1 dnote the areas of triangles ABC and AKL respectively, show that
\frac {E}{E_1} \geq 2.
Izvor: Međunarodna matematička olimpijada, shortlist 1988