Graphing a line

• To graph a line, the equation needs to be in slope intercept form

• y = mx + b

• m = the slope

• b = the y-intercept (where the lines crosses the y-axis)

Example: y = 1/2x + 6

• The slope is where the "m" would be

• So here, the slope is 1/2

• The y-intercept is where the "b" would be

• So here, the y-intercept is 6

To graph a line:

• Look for the y-intercept (the "b" in the equation)

• Plot that point on the y-axis

• Look at the slope (the "m" in the equation)

• Move that many units up and over from your first point.

• Remember: Positive slope goes up and over. Negative slope goes down and over.

​Horizontal and Vertical Lines

VERTICAL LINE

Vertical Lines go up and down

EVERY vertical line has the same equation: x = #.

The line to the right is x = 3.

VERTICAL LINE

EVERY point on a vertical line has the same x-coordinate.

The line graphed is x = 3.

EVERY point on that line is (3,#)

You can see some examples labeled on the graph.

HORIZONTAL LINE

Horizontal Lines go left and right

EVERY horizontal line has the same equation: y = #.

The line to the right is y = -4.

HORIZONTAL LINE

EVERY point on a horizontal line has the same y-coordinate.

The line graphed is y = -4.

EVERY point on that line is (#,-4)

You can see some examples labeled on the graph.