Key learning points

1. When presented with a real-life problem, it can help to sketch what is happening.
2. A sketch can provide a visual aid for understanding.
3. In there is a context to the problem then the solution should be given in context.

Common misconception

Keywords

• Linear - The relationship between two variables is linear if, when plotted on a pair of axes, a straight line is formed.

• Gradient - The gradient is a measure of how steep a line is.

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

• Parabola - A parabola is a curve where any point on the curve is an equal distance from a fixed point (the focus) and a fixed straight line (the directrix).