设 有连续的偏导数， 且 ，则 =（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/63eb2ad0bac447489cbf8cbb923d3692.png
举一反三
- 设有连续的偏导数，且，则 =（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/63eb2ad0bac447489cbf8cbb923d3692.png
- 函数在点处是连续的且偏导数也是存在的。（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/66eeff13d1904738bea6f4255ed45e69.png
- 设z=f(x,v) ，v=v(x,y) ，其中f,v具有一阶连续偏导数，则（ ）。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/64ca8940dd6e4835901f2da3b85b7607.png
- 若http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/5c06779096154f7c8b702d66edce8df1.png在点http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/7d26b1d151c9438485fa20b9ca38af20.png处可微，则偏导数http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/518027493bf540a1a080f49503d0afb3.png一定连续。<br>
- 设 与 复合而得到函数 .若在点可导, 对具有连续偏导数, 则复合函数 在点可导, 且 。（ ）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201803/9407bba37a6e4e34826276c13978a22a.png