The Slope of a Line
Find the slope of the line that passes through the points (3, 2) and (3, -4).
|Let (x1, y1) = (3, 2) and (x2, y2)
= (3, .4).
|Substitute these values in the slope formula.
|Since division by zero is undefined, the slope is undefined.
In fact, the slope of any vertical line is undefined.
Slope of a Line
We can use slope to help us construct the graph of a line.
|â€¢ Slope is positive: Line slants
upward as we move from left to
â€¢ Slope is negative: Line slants
downward as we move from left
â€¢ Slope is zero: The slope of a
horizontal line is 0.
â€¢ Slope is undefined: The slope
of a vertical line is undefined.
Graph the line that passes through the point (-5, 6) with slope
First, plot the given point, (-5, 6).
To find another point on the line, use the slope. The slope,
, tells us how to move up and down (rise) and left and right (run) to get to
another point on the line. The slope
says to move 3 units
down and 4 units right to get to another point, (-1, 3).
Plot the point (-1, 3).
Finally, draw a line through the two points.