# When the slope is 0 What does that mean?

Now we see why a vertical line has an undefined

**slope**. Because we can't divide by zero! Usually in math, when something is "undefined"**it means**that somewhere, something is being divided by**0**. And that's a no-no. It has no**meaning**.A.

### What happens when the slope has a 0 on top?

When the

**0**is on the "**top**" of the fraction, that would mean that the two y-values are the same. Thus that line is horizontal (**slope**of**0**).**If**the "bottom" of the fraction is**0**that means the two x-values are the same. Thus that line is vertical (undefined**slope**).#### How do you graph a slope?

**Algebra 1 – How to Graph a Linear Equation Using Slope and y**- Step 1: Put the equation in Slope Intercept Form.
- Step 2: Graph the y-intercept point (the number in the b position) on the y-axis.
- Step 3: From the point plotted on the y-axis, use the slope to find your second point.
- Step 4: Draw your line using the two points you plotted (y-intercept (b) first, slope (m) second.

#### How do you find the slope and y intercept of a line?

The coordinates of every point on the line will solve the equation if you substitute them in the equation for x and**y**. The equation of any straight line, called a linear equation, can be written as:**y**= mx + b, where m is the**slope**of the line and b is the**y**-**intercept**.#### What is the horizontal line?

In geometry, a**horizontal line**is one which runs from left to right across the page. It comes from the word 'horizon', in the sense that**horizontal lines**are parallel to the horizon. The horizon is**horizontal**. Its cousin is the vertical**line**which runs up and down the page.

B.

### What do you do if the slope is 0?

Since we did not have a change in the x values, the denominator of our

**slope**became**0**. This means that we have an undefined**slope**. If you were to graph the line, it would be a vertical line, as shown above. This form can be handy if you need to find the**slope**of a line given the equation.#### How do you know when a slope is steep?

When you look at the two lines, you can see that the blue line is steeper than the red line. It makes sense the value of the**slope**of the blue line, 4, is greater than the value of the**slope**of the red line, . The greater the**slope**, the steeper the line. The next example shows a line with a negative**slope**.#### Is a horizontal line undefined?

It**is a vertical line**through 2 on the - axis.**Vertical Lines**A**vertical line**is a**line**whose equation is of the form =ℎ, where ℎ is a real number. All points that lie on the**line**have an -coordinate of ℎ. The slope of any**vertical line**is**undefined**.#### How does a graph fail the vertical line test?

To use the**vertical line test**, take a ruler or other straight edge and draw a**line**parallel to the y-axis for any chosen value of x. If the**vertical line**you drew intersects the**graph**more than once for any value of x then the**graph**is not the**graph**of a function.

Updated: 7th September 2018