> <span class="n">a</span><span class="p">,</span> <span class="kt">double</span> <span class="n">b</span><span class="p">,</span> <span class="kt">double</span> <span class="n">c</span><span class="p">,</span>
               <span class="kt">double</span><span class="o">&amp;</span> <span class="n">root1</span><span class="p">,</span> <span class="kt">double</span><span class="o">&amp;</span> <span class="n">root2</span><span class="p">)</span> <span class="p">{</span>
    <span class="kt">double</span> <s