Points $A,B,C$ have coordinates $(-2,1)$, $(1,3)$ and $(7,7)$ respectively. Use vectors to s

Question

Points $A,B,C$ have coordinates $(-2,1)$, $(1,3)$ and $(7,7)$ respectively. Use vectors to show that $A,B,C$ are collinear.[3] Find $AB:BC$.[1]

Accepted Answer

(a) $\overrightarrow{AC}=3\overrightarrow{AB}$, common point $A$ (b) $1:2$

Collinearity from a common point