GRAPHING GUIDE
Start with the graph
An x-intercept is a point where y equals zero. A y-intercept is a point where x equals zero. The origin can be both.
Worked example
Plot y = 2x − 6. Find where the line meets each axis. Setting y = 0 gives 2x = 6, so the x-intercept is (3, 0). Setting x = 0 gives the y-intercept (0, −6).
Try another example
Plot y = x² − 4. The x-intercepts are (−2, 0) and (2, 0), while the y-intercept is (0, −4). A curve may touch the x-axis without crossing it, as y = x² does at the origin.
Check your result
Check that the viewing window includes both axes. If a crossing looks approximate, substitute its coordinate into the original equation.
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