tes the integrand for problem 2.
        </li>
        <li>
          <b>P02_TITLE</b> returns the title for problem 2.
        </li>
        <li>
          <b>P03_EXACT</b> returns the exact integral for problem 3.
        </li>
        <li>
          <b>P03_FUN</b> evaluates the integrand for problem 3.
        </li>
        <li>
          <b>P03_TITLE</b> returns the title for problem 3.
        </li>
        <li>
          <b>P04_EXACT</b> returns the exact integral for problem 4.
        </li>
        