How to find a point along a line a certain distance away from another point

Hi,

I have a line between two points : P1 = (x1,y1) and P2= (x2,y2). I have linear function equation : y = ax + b I want to extend a line a distance about 10 from P1 and P2 (in each direction left and right -) I need to find new points P3 and P4 on this line. I don"t have any idea how to move point a distance on the line ?

I would be appreciate for any help please.

[Adam]

Sounds like a question you should work out on paper before you do it in Matlab if you aren't familiar with the maths itself.

Answer 1

[KSSV]

Read this link:

http://math.stackexchange.com/questions/175896/finding-a-point-along-a-line-a-certain-distance-away-from-another-point

[agatte]

Thanks !!! good hint

[shalvi singh]

nice documentation..Thanks!