| 教材完全解读高中数学必修五的第30页的第九题AC=<span style="font-family: Tahoma, Arial, Helvetica, sans-serif, SimSun; font-size: 14px; line-height: 26px;">√AD²-CD²-2ADCDcos66°错了吧，不应该是AC=</span><span style="font-family: Tahoma, Arial, Helvetica, sans-serif, SimSun; font-size: 14px; line-height: 26px;">√AD²+CD²-2ADCDcos66°吗？</span> |
