span><span class="identifier">m_radius</span><span class="special">,</span> <span class="identifier">x</span><span class="special">);</span>
      <span class="identifier">T</span> <span class="identifier">k</span> <span class="special">=</span> <span class="identifier">sqrt</span><span class="special">(</span><span class="number">1</span> <span class="special">-</span> <span class="identifier">b</span> <span class="special">*</span> <span class="identifier">b</span> <span class="special">/</span> <span cla