Lines and points
The equation of a straight line is given by:
where a is the slope of the line. If a = 0, the line is horizontal. b indicate the intersection of the line with the y-axis.
Finding the equation of a line, when two points are given
It’s possible to find the equation of a straight line, when two of its points are given:
(x1,y1) and (x2, y2).
First you have to determine a and b of the equation of a straight line:
a and b can then be substituted into the equation of a straight line.
Finding the equation of a line, when a point and the line’s slope is given
The equation of a straight line passing through the point (x0, y0) and with the slope a is given by:
If the angle θ between the x-axis and the line is given instead of the slope a, it’s possible to calculate a in the following way: