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Kvant 2021
M2634
M2634
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Kvant 2021
Problems
(1)
Geometry with parabola
Source: Kvant Magazine No. 1 2021 M2634
3/9/2023
Consider a parabola. The parabolic length of a segment is the length of the projection of this segment on a straight line perpendicular to the axis of symmetry of the parabola. In the parabola, two chords
A
B
AB
A
B
and
C
D
CD
C
D
are drawn, intersecting at the point
N
N{}
N
. Prove that the product of the parabolic lengths of the segments
A
N
AN
A
N
and
B
N
BN
BN
is equal to the product of the parabolic lengths of the segments
C
N
CN
CN
and
D
N
DN
D
N
.Proposed by M. Panov
parabola
geometry
Kvant