On a two-dimensional graph representing two variables:
A)a positive slope of a curve means the variables are negatively related.
B)a negative slope of a curve means the two variables are positively related.
C)a line that is horizontal has a zero slope.
D)a line that is vertical has a zero slope.

Question

Quizplus · Accepted Answer

A horizontal line has a slope of zero because it does not have any change in the y-axis value for every unit change in the x-axis value. Choices A and B are incorrect because a positive slope means the variables are positively related while a negative slope means the variables are negatively related. Choice D is also incorrect because a vertical line does not have a slope and is undefined because it has an infinite slope.

On a Two-Dimensional Graph Representing Two Variables