J an 2 00 7 How to compute ∑ 1 / n 2 by solving triangles
نویسندگان
چکیده
The problem of computing the exact value of ∑ 1/n is so classical (dating back to 1644) that it even has a name of its own: the Basel problem. The city of Basel was the hometown both of the famous brothers Jakob and Johann Bernoulli, who made serious but unsuccessful attempts to solve the problem, and to the prodigious mathematician Leonhard Euler, who found the first solution in 1735, see [3]. Since then a great many different ways of evaluating the sum have been discovered. Fourteen proofs are collected in [2], and two of them have been in included in [1].
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