Key learning points

1. Two lines are parallel if they are equidistant and never touch.
2. For linear graphs, the rate of change is constant.
3. If the gradients are the same then the linear graphs may be parallel.
4. The y-intercepts must be different, otherwise the lines are the same.

Common misconception

Keywords

• Gradient - The gradient is a measure of how steep a line is. It is calculated by finding the rate of change in the y-direction with respect to the positive x-direction.

• Intercept - An intercept is the coordinate where a line or curve meets a given axis.

• Parallel - Two lines are parallel if they are straight lines that are always the same (non-zero) distance apart.