An inequality for complete elliptic integrals
In [the second author and \textit{J. Pfaltzgraff}, J. Math. Anal. Appl. 179, No. 1,110-119 (1993; Zbl 0797.31009)] it has been proved that \[ c_ 1 m(Q)\leq \mu(Q)\leq c_ 2 m(Q), \] where \(\mu(Q)\), \(m(Q)\) denote, respectively, the Robin modulus, and the exterior modulus of the rectangle \(Q\), and \(c_ 1\), \(c_ 2\) are some positive absolute constants. In the present paper the best values of the constants are given.
scientific article; zbMATH DE number 567013