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Putnam
1974 Putnam
A5
A5
Part of
1974 Putnam
Problems
(1)
Putnam 1974 A5
Source: Putnam 1974
5/28/2022
Consider the two mutually tangent parabolas
y
=
x
2
y=x^2
y
=
x
2
and
y
=
ā
x
2
y=-x^2
y
=
ā
x
2
. The upper parabola rolls without slipping around the fixed lower parabola. Find the locus of the focus of the moving parabola.
Putnam
Locus
parabola
geometry