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Putnam
Putnam 1938
B4
B4
Part of
Putnam 1938
Problems
(1)
Putnam 1938 B4
Source:
8/20/2021
The parabola
P
P
P
has focus a distance
m
m
m
from the directrix. The chord
A
B
AB
A
B
is normal to
P
P
P
at
A
.
A.
A
.
What is the minimum length for
A
B
?
AB?
A
B
?
Putnam