• 2021-04-14
    已知向量的两个方向余弦分别为,则向量的单位向量为 。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/ddccbadd28ff4393bdbc528098c1dc43.pnghttp://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/7904ae829dab4b16ad7979ea93482956.pnghttp://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/4c2541850dba41bbaf0047a783702fb8.png
  • http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/866873ace0314b64b7d91ffa01354fe1.png

    举一反三

    内容

    • 0

      设函数http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/2483d32f49ee48579b3a0f795ffeb08e.png,则http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/a038cd64e1d845ebb5779107a4d344a1.png(    )

    • 1

      设http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/90c19a717ac34717836dbca4afba1bd9.png是由方程http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/7648e783c2f24044bb84346d0e07e161.png确定,求http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/d24ed3aef9a94d38965289947da528f7.png(     )

    • 2

      设积分区域D由http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/0c9ae1ed54164a58bd49dd327b8b9613.png和http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/106bacc400de4a258c3c2cc1e88f5e50.png围成,则http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/533bf3bfe8d7439fbe2689a974be1cf1.png(&nbsp; &nbsp; )<br>

    • 3

      下列函数中为奇函数的是( ) A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/7d0e4f5547744249b8c4c0e6db0e62fc.png"> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/d19abeb7724248dca0a0c1b8017897db.png"> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/3f5cff0b4a9b441da3b9e75bd446c141.png"> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201908/d59a9db29be640a899356a3f1645a0dd.png">

    • 4

      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>