Question

Marcus plots the point (4, 7) in Quadrant I on the coordinate plane. Nicole then plots the point (4, –3) in Quadrant IV of the same graph. Explain what the line that goes through those two points would look like, and evaluate the slope.

Answer 1

The line would look like a vertical straight line at x = 4.

The slope would be undefined since the line is not a function.

Answer 2

Sample Response: Since both points have the same x-coordinate, the line would be vertical. A vertical line has no slope because the run of the graph, which is the denominator, is zero and therefore an undefined fraction.