1 . 凸四边形
的边
的中点分别为
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ba48366317ebea1c9dd5e4e67e03092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cf9b288c48c73463a2f214f02b6952a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65cca849a71bae840993bd051994db3e.png)
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2 . 已知向量
为平面向量,若
与
的夹角为
,
与
的夹角为
,则![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/74f435c6f6e541d38826425ea6551849.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/827fca3d374543d6844020ca8abfafad.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/181683c9ffaf4e8cbd0abdf3d428e2fa.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/b1738746545f49cc905bb047971d07ee.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/124413f37622406c9effc9541335d55d.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/181683c9ffaf4e8cbd0abdf3d428e2fa.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/28dc18d02dad434cbde2dcd5c2451b6b.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/6dca055adea64adc952f6194a2ed7b12.png)
![](https://img.xkw.com/dksih/QBM/2016/10/13/1573068666142720/1573068672172032/STEM/74f435c6f6e541d38826425ea6551849.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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3 . 已知向量
=(sinθ,cosθ﹣2sinθ),
=(1,2).
(Ⅰ)若
//
,求tanθ的值;
(Ⅱ)若|
|=|
|,求sin(2
)的值.
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/0954a8ae2213420a89b1b9abaed90fa5.png)
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/0378535100c4411cb41ea04d7403bdfe.png)
(Ⅰ)若
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/3879bdfc8e904462b37680954f55ce1e.png)
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/72e45b22cbd04adabdad5a4c740326a4.png)
(Ⅱ)若|
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/3879bdfc8e904462b37680954f55ce1e.png)
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/72e45b22cbd04adabdad5a4c740326a4.png)
![](https://img.xkw.com/dksih/QBM/2015/11/5/1572280113553408/1572280119631872/STEM/d5145a2aeb1f4a9689bcedd98298a3da.png)
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4 . 已知向量
,若
,则实数
的值为
![](https://img.xkw.com/dksih/QBM/2016/8/4/1572959373361152/1572959379169280/STEM/5af87d38fa6d47b3a4923cbaf66fd0a2.png)
![](https://img.xkw.com/dksih/QBM/2016/8/4/1572959373361152/1572959379169280/STEM/80f45a8966424763af23405bd398005c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5fffd330dd6b9241659d790bd2a7fb2.png)
A.1 | B.2 | C.-1 | D.-2 |
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10-11高二下·云南红河·阶段练习
5 . 在空间四边形ABCD中,若
,
,
,用
表示
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1887a1513aee097a396e99d7399c4e22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f2a9caf108675ee550eb04a0b389df4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ee72ce4f36a71e410d36eba1fb97037.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/660e5086aaf51a59324758d4648837de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbba7bff7720b3aa33f29936ede7819e.png)
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6 . 已知
,向量
的夹角为120°,且
,则实数t的值为
![](https://img.xkw.com/dksih/QBM/2015/7/16/1572184568242176/1572184573648896/STEM/a2e07a0d4dce479c89e5046579a7e7c0.png)
![](https://img.xkw.com/dksih/QBM/2015/7/16/1572184568242176/1572184573648896/STEM/565f2c96b48a444897b42476237f546b.png)
![](https://img.xkw.com/dksih/QBM/2015/7/16/1572184568242176/1572184573648896/STEM/a9d198f3af2049bc82d0e5f8dda32f25.png)
A.-2 | B.-1 | C.1 | D.2 |
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7 . 已知向量
满足
,且
,则
与
的夹角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c69613bda5b1face9751a8c13ae757ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47f836d905839bfafd9a4131b4eb18ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47bb185c1a3fb3abe9088ed5250ad554.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/696bf63a3a726968a19b8927be5a2112.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01b5960e052f614ae45628785cb2cbf4.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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8 . 已知点A(1,3),B(4,﹣1),则与向量
同方向的单位向量为
![](https://img.xkw.com/dksih/QBM/2016/9/12/1573016260165632/1573016265703424/STEM/61ba476b2431458c9a4493223afb51c9.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . 在长方体ABCD﹣A1B1C1D1中,
=
![](https://img.xkw.com/dksih/QBM/2016/3/18/1572546232901632/1572546238734336/STEM/6e8d76e740d04b2cb9c7d909dbab5a93.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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10 . 若向量
,
,若
与
的夹角为钝角,则实数
的取值范围为_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/244d17e3c570a30b4caf6016b5585664.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/840e6dc7eec01e1e96bc3056d60195d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2f4b1178f68bd147d1a2a6acd04435.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c94075193c11fe43f2396cff5a485054.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
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