   <b>SEC_DEG</b> returns the secant of an angle given in degrees.
        </li>
        <li>
          <b>SIGMA</b> returns the value of SIGMA(N), the divisor sum.
        </li>
        <li>
          <b>SIGMA_VALUES</b> returns some values of the Sigma function.
        </li>
        <li>
          <b>SIN_DEG</b> returns the sine of an angle given in degrees.
        </li>
        <li>
          <b>SIN_POWER_INT</b> evaluates the sine power integral.
        </li>
        <li>
          <b>SIN_POWER_INT_V