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Ramanujan's Inverse Elliptic Arc Approximation

Mark B. Villarino
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Abstract

We suggest a continued fraction origin to Ramanujan's approximation to {(a-b)/(a+b)}^2 in terms of the arc length of an ellipse with semiaxes a and b. Moreover, we discuss the asymptotic accuracy of the approximation.

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Mark B. Villarino. 2005-06-20. Ramanujan's Inverse Elliptic Arc Approximation. https://arxiv.org/abs/math/0506385

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