Practice!

Sample Problem

A. (0, 4), (0,7)

B. (4,9), (7,9)

C. (2,-3), (4,0)

D. (1,4), (3,1)

Which set of points depict a:

1) Falling line?

2) Rising line?

3) Horizontal line?

4) Vertical line?

Solution

1)The y-coordinate of line D decreased when the x-coordinate of line D increased, so it is falling..

2) The y-coordinate of line C increased when the x-coordinate of line C increased, so it is rising.

3) Line B has two of the same y-values, so it is a horizontal line through y = 9.

4) Line A has two of the same x-values, so it is a vertical line striking through x = 0. This line is the y-axis.