设 f 的导数连续， 是由 所围封闭曲面内侧，则https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/9a8faf24230c4485845bb5adabd15b5a.png
举一反三
- 下列方程所对应的曲面为双曲抛物面的是（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/3d9f8275e809414fb56a08f8128ba5d0.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/08c3e00fc9dd4a8c80260f92cbe9abd8.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/eda72acdb3ae4cf189947af5eefee38d.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/4ef0c2211e5840aea14a76e80e8965a5.png" />
- 如果具有二阶连续偏导数，则https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/00a66bfde04645bab10d1dc527f6eb6b.png
- 设A=<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/bc546fc03fdb4ba3b7e6b144b6371d7f.png" />，B=Р(Р(A)) 下列（ ）表达式不成立。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/6e615703da60435893f9e9a9273e12e5.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/64c831067d054e71a6c76f43849d450d.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/72023a5250e44c12b98923044194f13d.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/c48e039a739c4502830eee7ae0ac1678.png" />
- 向量场 穿过由曲面 与 所围成的封闭曲面S之外侧的通量为( ).https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/e0d05c3c859c43c69fe4ff54f5032220.png
- 设论域为整数集，下列公式中值为真的是（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/2711e476b621420282b7b5a9e859fa6b.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/170e20f6765346308a85d187b2cb10e9.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/7dde811e51824a06a3e118fe0c07d6fb.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/e2efbc62e6bc46e1b21e083664b89585.png">