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# Drawing graphs

### The Cartesian coordinate system

• The Cartesian coordinate system is a grid which uses two axes of reference — a horizontal or $$x$$-axis and a vertical or
$$y$$-axis.
• These two axes intersect at a point called the origin.
• Any point can be described exactly by using an ordered pair of numbers associated with it in the Cartesian Plane — it’s
($$x$$-coordinate, $$y$$-coordinate), and abbreviate this to $$(x, y)$$.
• The $$x$$ and $$y$$-axes divide the Cartesian plane into quarters. These quarters are called quadrants and are numbered as in the figure: