Equations of a straight line
In this unit we find the equation of a straight line, when we are given some information about the line. The information could be the value of its gradient, together with the co-ordinates of a point on the line. Alternatively, the information might be the co-ordinates of two different points on the line. There are several different ways of expressing the final equation, and some are more general than others.
Properties of straight line segments
In this unit we use a system of co-ordinates to find various properties of the straight line between two points. We find the distance between the two points and the mid-point of the line joining the two points.