span> <span class="keyword">double</span><span class="special">&gt;</span> <span class="identifier">estimated</span> <span class="special">=</span> <span class="identifier">estimate_polynomial_roots</span><span class="special">(</span>
      <span class="identifier">gen</span><span class="special">,</span>
      <span class="special">[</span><span class="identifier">root1</span><span class="special">,</span> <span class="identifier">root2</span><span class="special">](</span><span class="keyword">double</sp