名校
解题方法
1 . 如图,在平行四边形ABCD中,BD,AC相交于点O,设向量
,
.
![](https://img.xkw.com/dksih/QBM/2022/5/24/2986258300076032/2995511888650240/STEM/9de97c5c-711a-4ef4-bcac-847b592df251.png?resizew=256)
(1)若
,
,
,求证:
;
(2)若点P是平行四边形ABCD所在平面内一点,且满足
,求△ACP与△ACD的面积比;
(3)若
,
,点E,F分别在边AD,CD上,
,
,且
,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e7a93a1399ff7a2bde342652479241b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3b54aa2b7f9adf409f0ce8e00615432.png)
![](https://img.xkw.com/dksih/QBM/2022/5/24/2986258300076032/2995511888650240/STEM/9de97c5c-711a-4ef4-bcac-847b592df251.png?resizew=256)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b82d16399c8b393539c774d06f410cbe.png)
(2)若点P是平行四边形ABCD所在平面内一点,且满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfcc49ef13196d82c91f1291b436616a.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/27db558e8db4c957654c8e5cecd2d2dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55881285c3bea9e25144254cf2037540.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da346525c48808ae3dca8a05e4408b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dec945b565730ef11fe66334927dede1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bc29cb1d0b8ca9c4d6286c892952653.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febf7413b35cf2889fdb57a6b519087c.png)
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名校
2 . (1)如图,
,
不共线,
是直线
上的动点,证明:存在实数
,
,使得
,并且
.
![](https://img.xkw.com/dksih/QBM/2022/4/25/2965894555860992/2967921927028736/STEM/1cb3760a-d6bf-42c6-8e0c-e520bd49157b.png?resizew=144)
(2)用向量法证明下列结论:三角形的三条中线交于一点.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cec64476aaca08de0808afda3618109c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03b0ab2519d0fb666743993961daee47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1100379a4385b9ce064847bc21760adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c86ae785512262461ee99e1a724f4f1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6096acdd2d0ce16e1e45397ec5e365d4.png)
![](https://img.xkw.com/dksih/QBM/2022/4/25/2965894555860992/2967921927028736/STEM/1cb3760a-d6bf-42c6-8e0c-e520bd49157b.png?resizew=144)
(2)用向量法证明下列结论:三角形的三条中线交于一点.
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