Question

A line passes through the two given points. Is it vertical , horizontal ,or neither ? (-1, -1), (-2, -1)

Answer 1

Hello!

A line is horizontal is the slope is 0/x (slope of zero). It is vertical (undefined) if the slope is x/0. Anything else is neither.

The formula for the slope is seen below.

$\frac{ y_{2} - y_{1} }{ x_{2}- x_{1} }$

The twos and ones represent either one of the y-values or x-values on the line (or one one of the ordered pairs we are given). Any ordered pair can represent the ones or twos and the slope will be the same.

We will have (-1,-1) be ($x_{1} , y_{1}$) and (-2,-1) be ($x_{2} ,y_{2}$). We will plug these numbers into the equation.

$\frac{-1+1}{-2+1} = -\frac{0}{1}$

Therefore our slope is $- \frac{0}{1}$.

As I said before, a line is vertical if the slope is 0/x. Since this slope is zero divided by a number, the line is horizontal.

I hope this helps!