# How Do You Know If A Slope Is Undefined?

## Can the slope of a line be undefined?

The slope of a line can be positive, negative, zero, or undefined.

A horizontal line has slope zero since it does not rise vertically (i.e.

y1 − y2 = 0), while a vertical line has undefined slope since it does not run horizontally (i.e.

x1 − x2 = 0)..

## What does it mean to have a slope of 0 and an undefined slope?

Remember, a horizontal (flat) line has a slope of 0. A Vertical line (one that forms a right angle or is perpendicular to a flat line) has an undefined slope.

## What happens when the numerator is 0 in slope?

If the numerator of the fraction is 0, the slope is 0. This will happen if the y value of both points is the same. The graph would be a horizontal line and would indicate that the y value stays constant for every value of x.

## How do you know if a slope is zero or undefined?

A horizontal line has a slope of zero. When there is no change in x as y changes, the graph of the line is vertical. You could not compute the slope of this line, because you would need to divide by 0. These lines have undefined slope.

## What does 0 slope look like?

Put simply, a zero slope is perfectly flat in the horizontal direction. The equation of a line with zero slope will not have an x in it. It will look like ‘y = something.

## What if the slope is undefined?

1 Answer. If the slope of a line is undefined, then the line is a vertical line, so it cannot be written in slope-intercept form, but it can be written in the form: x=a , where a is a constant.