e.m">p26_title.m</a>, 
          prints a title for problem 26.
        </li>
        <li>
          <a href = "p27_default.m">p27_default.m</a>, 
          sets default values for problem 27.
        </li>
        <li>
          <a href = "p27_exact.m">p27_exact.m</a>, 
          sets the exact integral for problem 27.
        </li>
        <li>
          <a href = "p27_f.m">p27_f.m</a>, 
          evaluates the integrand for problem 27.
        </li>
        <li>
          <a href = "p27_i4.m">p27_i4.m</a