# High School Math : Understanding Vertical and Horizontal Lines

## Example Questions

### Example Question #1 : Vertical And Horizontal Lines

Which of the following is a horizontal line?

Explanation:

A horizontal line has infinitely many values for , but only one possible value for . Thus, it is always of the form , where  is a constant. Horizontal lines have a slope of . The only equation of this form is

### Example Question #1 : Understanding Vertical And Horizontal Lines

Which of the following is a vertical line?

Explanation:

A vertical line is one in which the  values can vary. Namely, there is only one possible value for , and  can be any number. Thus, by this description, the only vertical line listed is

### Example Question #1 : Linear Functions

Which of the following has a slope of 0?

Explanation:

A line with a slope of zero will be horizontal. A horizontal line has only one possible value for , and  can be any value.

Thus, the only given equation which fits this description is .

### Example Question #3 : Vertical And Horizontal Lines

Which of the following is a vertical line?

Explanation:

A vertical line has infinitely many values of  but only one value of . Thus, vertical lines are of the form , where  is a real number. The only equation of this form is