题目内容
| AM |
| 1 |
| 3 |
| AB |
| AN |
| 1 |
| 4 |
| AC |
| BP |
| PN |
| PM |
| CP |
| λ |
| μ |
分析:选取
、
为基向量,分别在△ANP、△AMP中利用三角形法则表示出
,根据平面向量基本定理可知表示唯一,从而得到方程组,解出μ、λ,进而得到答案.
| AB |
| AC |
| AP |
解答:解:
=
+
=
+
=
+
(
-
)
=
+
(
-
)
=
+
,
=
+
=
+
=
+
(
-
)
=
+
(
-
)
=
+
,
所以
,解得
,
所以
=12,
故选D.
| AP |
| AN |
| NP |
| 1 |
| 4 |
| AC |
| 1 |
| λ+1 |
| NB |
=
| 1 |
| 4 |
| AC |
| 1 |
| λ+1 |
| AB |
| AN |
=
| 1 |
| 4 |
| AC |
| 1 |
| λ+1 |
| AB |
| 1 |
| 4 |
| AC |
=
| λ |
| 4(λ+1) |
| AC |
| 1 |
| λ+1 |
| AB |
| AP |
| AM |
| MP |
| 1 |
| 3 |
| AB |
| μ |
| μ+1 |
| MC |
=
| 1 |
| 3 |
| AB |
| μ |
| μ+1 |
| AC |
| AM |
=
| 1 |
| 3 |
| AB |
| μ |
| μ+1 |
| AC |
| 1 |
| 3 |
| AB |
=
| μ |
| μ+1 |
| AC |
| 1 |
| 3(μ+1) |
| AB |
所以
|
|
所以
| λ |
| μ |
故选D.
点评:本题考查平面向量基本定理及其意义,考查向量的线性运算,属中档题.
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