If ` vec P O+ vec O Q= vec Q O+ vec O R ,` show that the point, `P ,Q ,R` are collinear.

Explanation

let a,b,c are position vector then,

`(a−b)∥(a−c)`

`(a−b)=K(a−c)`

`PQ​+QO=QC+OR`

`OQ​−OP=OR−OQ`


`(OQ−OP)/(a−b)=(OQ−OR)​/(K(a−c)−1)`

`(OQ​−OP)∥(OQ−OR)`

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