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\begin{center}
\textbf{Trinomul patrat}
\end{center}

\begin{enumerate}
\item Ecuatia patrata $ax^2+bx+c=0,\ a\not=0$ are\\
      a) doua solutii distincte, daca $\Delta=b^2-4ac>0$
      $$
      x_1=\frac{-b-\sqrt{\Delta}}{2a},\qquad
      x_2=\frac{-b+\sqrt{\Delta}}{2a};
      $$\\
      b) doua radacini egale, daca
      $\ds\Delta=0,\quad x_1=x_2=-\frac{b}{2a}$;\\
      c) nu are solutii, daca $\Delta<0$.
\end{enumerate}

\begin{center}
\textbf{Cazuri particulare}
\end{center}

\begin{enumerate}
\item $\ds ax^2+2kx+c=0,\quad a\not=0,\ x_{1,2}=\frac{-k\pm\sqrt{k^2-ac}}{a}
      \quad (k^2-ac\geq 0).$
\item $\ds x^2+px+q=0,\quad x_{1,2}=-\frac{p}{2}\pm
      \sqrt{\left(\frac{p}{2}\right)^2-q}$, \ daca $p^2\geq 4q$.
\end{enumerate}

\footnotetext[0]{\quad Copyright$\copyright$1999 ONG TCV
    Scoala Virtuala a Tanarului Matematician \quad http://math.ournet.md}


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