Coordinates are used to describe the position of points on a grid. The main horizontal line on the grid is known as the x-axis and the main vertical line is the y-axis. Both axes are number lines with ...

Higher - The gradients of two perpendicular lines will always multiply to make –1. Make sure you are familiar with finding the equation of a line and calculating gradient to understand equations of ...

Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.