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1992 Poland - Second Round
6
6
Part of
1992 Poland - Second Round
Problems
(1)
x_{n+1} = (x_n+2)/(x_n+1) ,y _{n+1}=(y_n^2+2)/2y_n
Source: Polish MO Recond Round 1992 p6
9/9/2024
The sequences
(
x
n
)
(x_n)
(
x
n
)
and
(
y
n
)
(y_n)
(
y
n
)
are defined as follows: x_{n+1} = \frac{x_n+2}{x_n+1}, y_{n+1}=\frac{y_n^2+2}{2y_n} \text{ for } n= 0,1,2,\ldots. Prove that for every integer
n
≥
0
n\geq 0
n
≥
0
the equality
y
n
=
x
2
n
−
1
y_n = x_{2^n-1}
y
n
=
x
2
n
−
1
holds.
algebra
Sequence
recurrence relation