Journal of Inequalities and Applications 
Volume 4 (1999), Issue 2, Pages 115-139
doi:10.1155/S1025583499000326

Some inequalities for the Hersch–Pfluger distortion function

S.-L. Qiu,1 M. K. Vamanamurthy,2 and M. Vuorinen3

 1Hangzhou Institute of Electronics Engineering (HIEE), Hangzhou 310037, China
2Department of Mathematics, University of Auckland, Private Bag 92019, Auckland, New Zealand
3Department of Mathematics, P.O. Box 4 (Yliopistonk. 5), FIN-O0014 University of Helsinki, Finland
Received 17 February 1998; Revised 28 September 1998

Abstract

The authors obtain some new functional inequalities for the Hersch–Pfluger distortion function in the theory of plane quasiconformal mappings, thus solving some recent conjectures.