title: Plotting a Parametric Equation
body: <p>I would like to plot the following curve: <code>Ca(t) = (a + cos(t) , -2a^(2) + sin(t))</code>
  The goal is to plot a number of curves for <code>a = -2:0.1:2</code>.</p>
  
  <pre><code>clf
  a=zeros(1,41);
  for i=1:41
      a(i)=-2+(i-1)/10;
      x=linspace(0,2*pi);
      plot([a(i)+cos(x) -2*a(i)^2+sin(x)])
      hold on
      grid on
  end
  </code></pre>
  
  <p>This code doesn't seem to do the job. Can anyone help me? Or simplify my code. I know I could use the syms option, but how can I get a plot for all those different values of a.</p>