On Alzer and Qiu's Conjecture for Complete Elliptic Integral and Inverse Hyperbolic Tangent Function
On Alzer and Qiu's Conjecture for Complete Elliptic Integral and Inverse Hyperbolic Tangent Function
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DOI:
10.1155/2011/697547
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发表时间:
2011-01-01
影响因子:
--
通讯作者:
Qiu, Ye-Fang
中科院分区:
文献类型:
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作者:
Chu, Yu-Ming;Wang, Miao-Kun;Qiu, Ye-Fang
We prove that the double inequality (pi/2) (arthr/r)(3/4+alpha*r) < K(r) < (pi/2) (arthr/r)(3/4+beta*r) holds for all r is an element of (0, 1) with the best possible constants alpha* = 0 and beta* = 1/4, which answer to an open problem proposed by Alzer and Qiu. Here, K(r) is the complete elliptic integrals of the first kind, and arth is the inverse hyperbolic tangent function.