Experiment with the graph below by changing the parameters to see how it affects the graph.
You will often find that you need to find the equation of a line given a point on the line and the gradient.
As part of my series on coordinate geometry I show you how to find the distance between two points.
In this video I show you how to find the coordinates of the mid-point of a line segment.
In this next example, I show you how to find the equation of a parallel line to a given line passing through a given point.