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Putnam
1952 Putnam
B7
Putnam 1952 B7
Putnam 1952 B7
Source: Putnam 1952
July 7, 2022
Putnam
trigonometry
cosine
Convergence
Problem Statement
Given any real number
N
0
,
N_0,
N
0
,
if
N
j
+
1
=
cos
N
j
,
N_{j+1}= \cos N_j ,
N
j
+
1
=
cos
N
j
,
prove that
lim
j
→
∞
N
j
\lim_{j\to \infty} N_j
lim
j
→
∞
N
j
exists and is independent of
N
0
.
N_0.
N
0
.
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