题目内容
如图,在矩形OACB中,E和F分别是边AC和BC的点,满足AC=3AE,BC=3BF,若
=λ
+μ
其中λ,μ∈R,则λ+μ是( )

| OC |
| OE |
| OF |
A.
| B.
| C.
| D.1 |
在矩形OACB中,
=
+
,
,
=λ
+μ
=λ(
+
)+μ(
+
)=λ(
+
)+μ(
+
)=
+
,
∴
=1,
=1,
=2,
∴λ+μ=
,
故选 B.
| OC |
| OA |
| OB |
,
| OC |
| OE |
| OF |
| OA |
| AE |
| OB |
| BF |
| OA |
| 1 |
| 3 |
| OB |
| OB |
| 1 |
| 3 |
| OA |
| 3λ+μ |
| 3 |
| OA |
| 3μ+λ |
| 3 |
| OB |
∴
| 3λ+μ |
| 3 |
| 3μ+λ |
| 3 |
| 4μ+4λ |
| 3 |
∴λ+μ=
| 3 |
| 2 |
故选 B.
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