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Fie \( a,b,c\in \mathbb{R}\ ,\ a\neq 0 \) , astfel incat \( b^2<4ac \) . Aratati ca daca \( 4a+2b+c>0 \) , atunci :

\(
a+2b+4c>0 \) .


Bogdan Enescu , OJ 1995

Daca \( f(x)=ax^2+bx+c \) atunci \( f(2)\cdot f(\frac{1}{2})>0 \)