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Expressions for rational approximations to square roots of integers using Pell's equation

Published online by Cambridge University Press:  14 February 2019

Ken Surendran
Affiliation:
11204 Broad Green Drive, Potomac MD 20854, USA e-mail: [email protected]
Desarazu Krishna Babu
Affiliation:
16914 Fondness Park Drive, Spring TX 77379, USA e-mail: [email protected]

Extract

There are recursive expressions (see [1]) for sequentially generating the integer solutions to Pell's equation: p2 − Dq2 = 1, where D is any positive non-square integer. With known positive integer solution p1 and q1 we can compute, using these recursive expressions, pn and qn for all n > 1. See Table in [2] for a list of smallest integer, or fundamental, solutions p1 and q1 for D≤ 128. These (pn, qn) pairs also form rational approximations to that, as noted in [3, Chapter 3], match with convergents (Cn = pn / qn) of the Regular Continued Fractions (RCF, continued fractions with the numerator of all fractions equal to 1) for .

Type
Articles
Copyright
Copyright © Mathematical Association 2019 

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References

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