# Math Help - Vector problem

1. ## Vector problem

given that $\vec{OP}$=mi+9j, $\vec{OQ}$=6i+6j and $\vec{OR}$=12i+4j,find the value of m if point P,Q and R are collinear.

2. Take a look at this picture.

There you see vectors OQ and OR drawn.

3. Originally Posted by shenanigans87
Take a look at this picture.

There you see vectors OQ and OR drawn.

sir..how can i get the answer?

4. In order for P Q and R to be colinear they must lie on the same line. This is represented by the dashed line there. We already know the y coordinate of the missing vector. This is shown by the solid white line. So the x value must be somewhere on that line AND the dashed line. That's your answer.

5. Oops
I drew OQ wrong.I drew it as (6,9) but its supposed to.be (6,6).
Draw your own graph and find OP by finding the intersection of QR and y=9