若函数<img src="/lqwvjeImg/c3/c34d2ad0e272d3b7131eb1c424db4726.png"style="width:31px;height:19px;">在点<img src="/lqwvjeImg/75/757c3fed3ffc47f98f03ed7f56853872.png"style="width:20px;height:17px;">有导数,而<img src="/lqwvjeImg/37/37b8a03d7a86137020b9028c75f14a57.png"style="width:24px;height:14px;">在<img src="/lqwvjeImg/75/757c3fed3ffc47f98f03ed7f56853872.png"style="width:20px;height:17px;">处连续但导数不存在,则<img src="/lqwvjeImg/7d/7dc69245d0878a8da253f99072d695c7.png"style="width:112px;height:19px;">在点<img src="/lqwvjeImg/75/757c3fed3ffc47f98f03ed7f56853872.png"style="width:20px;height:17px;">处( )。<br>·一定有导数<br>·一定没有导数<br>·导数可能存在<br>· 一定连续但导数不存在