已知a,b向量不共线,OA向量=a+b,OB向量=2a-b.AC向量=2CB向量,则OC向量=A,(5/3 )*a+(1/3)*bB,(-5/3)*a-(1/3)*bC,(2/3)*a-(1/3)*bD(5/3)*a-(1/3)*b求过程
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![已知a,b向量不共线,OA向量=a+b,OB向量=2a-b.AC向量=2CB向量,则OC向量=A,(5/3 )*a+(1/3)*bB,(-5/3)*a-(1/3)*bC,(2/3)*a-(1/3)*bD(5/3)*a-(1/3)*b求过程](/uploads/image/z/15025063-31-3.jpg?t=%E5%B7%B2%E7%9F%A5a%2Cb%E5%90%91%E9%87%8F%E4%B8%8D%E5%85%B1%E7%BA%BF%2COA%E5%90%91%E9%87%8F%3Da%2Bb%2COB%E5%90%91%E9%87%8F%3D2a-b.AC%E5%90%91%E9%87%8F%3D2CB%E5%90%91%E9%87%8F%2C%E5%88%99OC%E5%90%91%E9%87%8F%3DA%2C%285%2F3+%29%2Aa%2B%281%2F3%29%2AbB%2C%28-5%2F3%29%2Aa-%281%2F3%29%2AbC%2C%EF%BC%882%2F3%EF%BC%89%2Aa-%EF%BC%881%2F3%EF%BC%89%2AbD%EF%BC%885%2F3%EF%BC%89%2Aa-%EF%BC%881%2F3%EF%BC%89%2Ab%E6%B1%82%E8%BF%87%E7%A8%8B)
已知a,b向量不共线,OA向量=a+b,OB向量=2a-b.AC向量=2CB向量,则OC向量=A,(5/3 )*a+(1/3)*bB,(-5/3)*a-(1/3)*bC,(2/3)*a-(1/3)*bD(5/3)*a-(1/3)*b求过程
已知a,b向量不共线,OA向量=a+b,OB向量=2a-b.AC向量=2CB向量,则OC向量=
A,(5/3 )*a+(1/3)*b
B,(-5/3)*a-(1/3)*b
C,(2/3)*a-(1/3)*b
D(5/3)*a-(1/3)*b
求过程
已知a,b向量不共线,OA向量=a+b,OB向量=2a-b.AC向量=2CB向量,则OC向量=A,(5/3 )*a+(1/3)*bB,(-5/3)*a-(1/3)*bC,(2/3)*a-(1/3)*bD(5/3)*a-(1/3)*b求过程
由
AC=OC-OA=OC-(a+b)
CB=OB-OC=(2a-b)-OC
已经知道:AC=2CB
即OC-(a+b)=2[(2a-b)-OC]
整理得:
3OC=5a-b
OC=(5a-b)/3
选择(D)