- #1
memomath
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Hello everybody
I have looked everywhere for some good guides, so the question is:
You probably know the Fibonacci sequence (1,1,2,3,5,8…) but there is a lesser-known sequence called (Pythagoras stairs) generated by a similar recursion formula.
This is a sequence of pairs (Xn,Yn) usually arranged as follows:
1 2
2 3
5 7
12 17
And so on……. It begins with (x1,y1)=(1,1) and the recursion formula is
X{n+1} = X{n} + Y{n}
Y{n+1} = X{n}+ X{n+1}
Prove by induction that always
Y^2 = 2 X^2 ± 1
Pythagoras used this equation to generate rational approximations to (2)^1/2
Thanks in advance for usefully discuss to solve for this interesting question
I have looked everywhere for some good guides, so the question is:
You probably know the Fibonacci sequence (1,1,2,3,5,8…) but there is a lesser-known sequence called (Pythagoras stairs) generated by a similar recursion formula.
This is a sequence of pairs (Xn,Yn) usually arranged as follows:
1 2
2 3
5 7
12 17
And so on……. It begins with (x1,y1)=(1,1) and the recursion formula is
X{n+1} = X{n} + Y{n}
Y{n+1} = X{n}+ X{n+1}
Prove by induction that always
Y^2 = 2 X^2 ± 1
Pythagoras used this equation to generate rational approximations to (2)^1/2
Thanks in advance for usefully discuss to solve for this interesting question
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