\begin{frame}
  \frametitle{Polynomials of Degree 2: Quadratic Functions}
  
  \begin{block}{}
    A polynomial of degree $2$ is a \emph{quadratic function}:\vspace{-.5ex}
    \begin{talign}
      f(x) = ax^2 + bx + c
    \end{talign}\vspace{-3ex}
  \end{block}\medskip

  \begin{minipage}{.49\textwidth}
  \begin{center}
  \scalebox{.6}{
  \begin{tikzpicture}[default]
    \diagram{-2}{2}{-2}{4}{1}
    \diagramannotatez
    \diagramannotatex{-1,1}
    \diagramannotatey{-1,1,2,3}
    \draw[cblue,ultra thick] plot[smooth,domain=-2:1.3,samples=20] (\x,{pow(\x,2) +\x + 1});
  \end{tikzpicture}
  }\\
  {\small $x^2 + x + 1$}
  \end{center}
  \end{minipage}
  \begin{minipage}{.49\textwidth}
  \begin{center}
  \scalebox{.6}{
  \begin{tikzpicture}[default]
    \diagram{-2}{2}{-2}{4}{1}
    \diagramannotatez
    \diagramannotatex{-1,1}
    \diagramannotatey{-1,1,2,3}
    \draw[cblue,ultra thick] plot[smooth,domain=-.7:2,samples=20] (\x,{-2*pow(\x,2) + 3*\x + 1});
  \end{tikzpicture}
  }\\
  {\small $-2x^2 + 3x + 1$}
  \end{center}
  \end{minipage}
  \bigskip
  \pause
  
  The graph of is always a shifting of the parabola $ax^2$. It open upwards if $a > 0$,
  and downwards if $a < 0$.
\end{frame}