\documentclass{article}

\usepackage[dvips]{graphicx}
\usepackage{amsmath,amsthm,amsfonts}
\usepackage{html,color}

\begin{document}

\problemset

\problem

Find the equation for the parabola shown below.

\maximacode
  pick([list]) := block([i], i:random(length(list))+1, return(list[i]));
  a: pick(-2,1/2);
  x0: pick(-2,0,1);
  x1: pick(2,3,4);
\endmaximacode

\begin{center}
\maximaplot [a*(x-x0)*(x-x1),x0-1,x1+1] \endmaximaplot
\end{center}

\multiplechoice
\correct
\maxima expand(a*(x-x0)*(x-x1)) \endmaxima
\incorrect
\maxima expand(-a*(x-x0)*(x-x1)) \endmaxima
\incorrect
\maxima expand((x-x0)*(x-x1)) \endmaxima
\incorrect
\maxima expand(-(x-x0)*(x-x1)) \endmaxima
\endmultiplechoice

\endproblemset

\end{document}
