Question

在△ABC中,点P在BC上,且向量BP=2向量PC,点Q是AC的中点,若向量PA=（4,3）,向量PQ=（1,5）,则向

Answer 1

BP = 2PC

Q是AC的中点

=> AQ= QC = (1/2)AC

PA=(4,3),PQ=(1,5)

BC = BP+PC

=3PC

= 3(PA +AC)

= 3(PA + 2AQ)

= 3(PA + 2(-PA+ PQ) )

= 3((4,3) + 2(-3,2))

= 3((-2,7))

=(-6,21)