<page xmlns="http://projectmallard.org/1.0/"
      xmlns:its="http://www.w3.org/2005/11/its"
      type="guide" style="2column task"
      id="r-formulae">

  <info>
    <link type="guide" xref="index#formulae"/>

    <desc>Explicit formulae for <em>r</em> (polar equations)</desc>
  </info>
  <title>Formulae of the form <em>r = f(θ)</em></title>

  <p>
    These can be entered into a formula box only in the form <code>r = f(θ)</code>.
  </p>

</page>
