IMO Shortlist 2017 problem G2
Kvaliteta:
Avg: 0,0Težina:
Avg: 6,0Let and
be different points on a circle
such that
is not a diameter. Let
be the tangent line to
at
. Point
is such that
is the midpoint of the line segment
. Point
is chosen on the shorter arc
of
so that the circumcircle
of triangle
intersects
at two distinct points. Let
be the common point of
and
that is closer to
. Line
meets
again at
. Prove that the line
is tangent to
.
Izvor: https://www.imo-official.org/problems/IMO2017SL.pdf