IMO Shortlist 1979 problem 25
Dodao/la:
arhiva2. travnja 2012. We consider a point

in a plane

and a point

. Determine all the points

from

for which

is maximum.
%V0
We consider a point $P$ in a plane $p$ and a point $Q \not\in p$. Determine all the points $R$ from $p$ for which $$\frac{QP+PR}{QR}$$ is maximum.
Izvor: Međunarodna matematička olimpijada, shortlist 1979