Below are examples of a GOOD graph for the linear equation y = 2x + 4 and a BAD graph for the linear equation y = 2x + 4. At the end of the post is a checklist that you can use to be sure you are creating GOOD graphs for all your linear equations.
Checklist for a good graph – Linear Equations
- Label the horizontal and vertical axes with the appropriate symbols.
- Identify tick marks (in this case distance is 10 in each direction from the origin).
- Plot and label at least two ordered pairs that are on the graph of the equation. If you have a third point, plot and label it just for checking purposes.
- Use a straightedge to connect the points and run the graph through and beyond the end points (unless the domain is restricted).
Note: The lack of closed endpoints on the graph indicates that it continues forever in each direction.