 insensitive to the model
      parameters.</p>

      <p>If there is damping in the original system, of course we can cancel
      this out, too, using $u = -k \dot\theta \tilde{E} + b\dot\theta.$  And
      once again, the controller is quite robust if we have errors in the
      estimated damping ratio.</p>

    </subsection>

  </section>

  <section><h1>Exercises</h1>

    <exercise><h1>Graphical Analysis</h1>

      <figure>
      <img width="60%" src="figures/exercises/graphical_analysis.svg"/>
     