Articolele autorului Ionel Catalin Barbu
Link la profilul stiintific al lui Ionel Catalin Barbu

New aspects of Ionescu–Weitzenbock’s inequality
Remarks on a new metric in the unity disc of the complex plane
Jordan type inequalities using monotony of functions
Andrica-Iwata’s Inequality in hyperbolic triangle

In this paper we proof the Andrica-Iwata's inequality for a hyperbolic triangle

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Some hyperbolic concurrency results in the Poincare disc

In this paper, we present a proof of some hyperbolic theorems in the Poincar´e Model of Hyperbolic Geometry.

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A Geometric Proof of Blundon’s Inequalities

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.

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