已知二维向量，，求由该向量所张成的平行四边形面积为（ ）.http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/576a136e5e9f43c3bfc3135a4954b4db.png
举一反三
- 已知二维向量，，求由该向量所张成的平行四边形面积为（）.
- 已知二维向量[img=65x24]17869fc307a7549.png[/img]，[img=77x24]17869fc310ed3e1.png[/img]，求由该向量所张成的平行四边形面积为（ ）. A: 10 B: 9 C: 11 D: 12
- 在电感元件的交流电路中，已知<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/a818ffec501541eaacdc3fd4b3458bfa.png" />，则（ ）。 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/70961d125a8a493cbdbd3169e8655336.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/65f4ae24f45041548b04d5bb8c113767.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/20d9ff741d534721b621dfe04fb3b2bd.png" />
- 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
- 理想气体卡诺循环过程的两条绝热线下的面积大小（图中阴影部分）分别为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/64280a32f9a4401f98f6b6af70e231df.png" />，则二者的大小关系是（ ）<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/780b6d8d2ff542618f571d6996cd2cab.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/beb26455791a4b07bce0ac35eba22212.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/4bdc821d2c3946d288266564f445e908.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/08c97c45c5d54526a81db7c2679f8fcf.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/6a476124a610477b9ebf6723989ae08c.png" />