title: How can I plot ± sqrt(x) in one function?
body: <p>Gnuplot uses only positive square root values when <code>sqrt(x)</code> is used. Is there a way to plot both positive and negative values in the same function.</p>
  
  <p>I know of a hack which is to use <code>f(x) = sqrt(x)</code> and <code>g(x) = -sqrt(x)</code> and plot them together and then adjust both functions to use the same line colors but is there a better way?</p>