Equations of horizontal and vertical lines
key notes:
The graph of x = -1 is a vertical line. Every x-value is -1, including the x-intercept.
The graph of y = -1 is a horizontal line. Every y-value is -1, including the y-intercept.
Learn with an example
Is the graph of this equation a horizontal or vertical line?
x = -1
The equation x = -1 tells you that every x-value is -1.
First plot some points that have an x-value of -1.
Now draw a line connecting the points.
The graph of x = -1 is a vertical line.
Is the graph of this equation a horizontal or vertical line?
y = 8
The equation y = 8 tells you that every y-value is 8.
First plot some points that have a y-value of 8.
Now draw a line connecting the points.
The graph of y = 8 is a horizontal line.
Let’s Practice!
