Lemma
•
•
Let
C
be the circle with center
(a, b)
that includes
the origin:
(x − a)
2
+ (y − b)
2
= a
2
+ b
2
. Let
C
r
,
P
,
Q
, and
R
be defined as in the Generalized
Shrinking Circle Problem.
•
•
Then
•
R
à
(4a, 0)
if
b = 0
•
R
à
( 0, 0 )
otherwise
•