Position vectors and the origin

1. Nov 2, 2007

rishic

hi
I got an IGCSE exam in two days and cant find any info on position vectors could sum1 please help me out. And does a position vector have to do with the origin

Last edited: Nov 2, 2007
2. Nov 2, 2007

cristo

Staff Emeritus
Well, where did you look? Do you have a textbook from which you are studying?

3. Nov 2, 2007

mjsd

you sure you can't find anything? not even google? wikipedia? maths world?

4. Nov 2, 2007

rishic

Im studying from the book, IGCSE mathematics by Ric Pimentel and Terry Wall. Wikipedia has the definition and all but nothing on how to apply the info. to questions. Google has nothing great either. I was trying to find out how you find the position vector of a point and whether the origin is required to do this?

5. Nov 2, 2007

mjsd

vector is a vector, it is a geometric object. a point in space is a point in space. the origin and a "coordinate system" is used only when you want to put things into component form. like (1,0,0). I guess you are referring to that. Now, you need think about first, which coordinate system do you want to use and where to put the origin. Once you have a coordinate system your "point" now has a coordinate (x,y,z) and your position vector is the ray going from the origin to the point , with components (x,y,z) - (0,0,0) = (x,y,z)