Learn how to find equations of parallel lines, work out the gradient of perpendicular lines, and prove that given lines are parallel or perpendicular.

This includes two given points where the right-hand point is given first, eg (2, 2) and (-4, -2). Q9 gives the information about a parallel line (both in the form y=mx+c and ay+bx=c). Q10 looks at ...

To write the equation of a line it is necessary to know the slope and the y intercept. There are three possibilities which depend on the data available.