Autori: Dorin Andrica, Cãtãlin Barbu
Editorial: Mathematical Inequalities & Applications , Volume 15, Number 2 , p.361-370, 2012.
A geometric approach of Blundon’s inequality is presented. Theorem 2.1 gives the formula for cosION in terms of the symmetric invariants s , R, r of a triangle, implying Blundon’s
inequality (Theorem 2.2). A dual formula for cosIaONa is given in Theorem 3.1 and this implies the dual Blundon’s inequality (Theorem 3.2). As applications, some inequalities
involving the exradii of the triangle are presented in the last section.
Cuvinte cheie: inegalitati // inequalities