mateforum.ro

Posted: **Mon Jul 14, 2008 6:15 am**

Demonstrati ca pentru orice numere \( a,b,c \in (0, \infty) \), are loc inegalitatea \( (a+b)(ab+1)+(b+c)(bc+1)+(c+a)(ca+1) \geq 4(ab+bc+ca) \).

Zdravko Starc, Revista Minus 1/2008

Posted: **Tue Jul 15, 2008 7:26 pm**

\( \sum {(a+b)(ab+1)}\geq\sum {2\sqrt{ab}2\sqrt{ab}}=4\sum {ab} \)

mateforum.ro

O inegalitate elementara

O inegalitate elementara