
Journal for Geometry and Graphics 12 (2008), No. 1, 011021 Copyright Heldermann Verlag 2008 A Method for Establishing Trigonometric Inequalities Involving the Cotangents of the Angles of a Triangle Jebrel M. Habeb Dept. of Mathematics, Yarmouk University, Irbid, Jordan jhabeb@yu.edu.jo Mowaffaq Hajja Dept. of Mathematics, Yarmouk University, Irbid, Jordan mowhajja@yahoo.com We find relations that define the cotangents of the angles of a general triangle, and we use these relations to describe a method for optimizing symmetric functions in the cotangents of such angles and for establishing trigonometric inequalities that involve such functions. Keywords: Geometric inequalities, extrema, trigonometric inequalities, trigonometric identities, cotangents, Brocard angle, discriminant. MSC: 51M16; 52B10 [ Fulltextpdf (195 KB)] for subscribers only. 