# How do you find the slope of #x = -3#?

##### 1 Answer

There an undefined slope. (No slope)

#### Explanation:

Generally, lines have the equation of

If the equation is

However, what you have there isn't any normal line. It's a vertical line. Let's try to plot this.

To plot, I'm going to put it into my calculator (If you want to, try using www.desmos.com/calculator, its a great web plotter)

As you can see, this line is *vertical*! It goes directly up. We know that because the equation says that **X is equal to -3**. It is telling us that no matter what the Y value is, X will be -3.

For example, if Y is 4, X will be -3. If Y is 400000032, x will be -3.

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So, let's prove that **a vertical line has an undefined slope.**

The equation to find slope is to take two points

So, let's take two points. Let's say that Y is equal to 3 and 2. In that case, since X is always -3, our points would be

Now, let's substitute into our formula.

As you can see, the final slope is *any number divided by zero is undefined*. And so your slope for **any vertical line** is undefined.

Cheers!