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i posted a while ago finding points on a line as i need to calculate if a given (X,Y) is on a line that spans from (x1,y1) to (x2,y2) i have the following
The equation of the line joining the points
is given by
Now, after forming the equation of the line joining the two points,
substitute the values (x,y) and see if the equation is satisfied. If yes, the point lies on the straight line, if no, it doesn't.
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