Standard Form
Horizontal & Vertical Lines
Examples
Example 1 Graph y = 4.
The only variable appearing is y. Regardless of which x-value is chosen, the y-value is always 4. All points with a y-value of 4 satisfy the equation. Thus the graph is a horizontal line 4 units above the x-axis.
Example 2 Graph x = ?2.
The only variable that appears is x. Regardless of which y-value is chosen, the x-value will always be ?2. The resulting graph is a vertical line two units to the left of the y-axis.