Chapter 8.3, Problem 22WE

To determine

To calculate: The slope of the line,

  $y+4=0$

Answer to Problem 22WE

Theslope of the line is zero.

Explanation of Solution

Given information:

Theequation of the lines:

  $y+4=0$

Formula used:

For finding the slope of the line:

  $m=\frac{y_2-y_1}{x_2-x_1}$ .

Calculation:

Consider the equation of line,

  $y+4=0$

Rewrite the equation:

  $\begin{array}{l}y+4=0\\ y=-4\end{array}$

The general equation of line is:

  $ax+b=y$

Here in this form this equation becomes:

  $\begin{array}{l}ax+b=y\\ 0x-4=y\end{array}$

For finding the slope of line when apply values in the formula,

  $m=\frac{y_2-y_1}{x_2-x_1}$

Check For the points $\left(-3,4\right),\left(2,4\right)$ ,the slope of the line is.

  $\begin{array}{c}m=\frac{y_2-y_1}{x_2-x_1}\\ m=\frac{4-4}{-3-2}\\ m=\frac{0}{-5}\\ m=0\end{array}$

Observe that, No result will found here,

So the slope of the equation $y+4=0$ , that is zero.

From here, $m=0$

The graph of every horizontal line is zero.

The graph of the line is horizontal line through $y+4=0$ .

A line that no rises , the slope of that line is zero.

Thus, the slope of the line is zero.