(1)如图,设点P,Q是线段AB的三等分点,若→ = →,→ = →,试用→→表示向量
OA a OB b a b → →
OP OQ
(2)如果点A1,A2,A3,A4依次是AB的等分点,求证 → + → = → + → (1≤k≤4)
OAk OA5-k OA OB
(1)如图,设点P,Q是线段AB的三等分点,若→ = →,→ = →,试用→→表示向量
OA a OB b a b → →
OP OQ
(2)如果点A1,A2,A3,A4依次是AB的等分点,求证 → + → = → + → (1≤k≤4)
OAk OA5-k OA OB
1.1/3倍b向量+2/3倍a向量,2/3倍b向量+1/3倍a向量
2.OAk 向量= OA 向量+Ak 向量= OA 向量+k/5倍(OB向量-OA向量)