Function Analysis: Determining Behavior When Dividing by -1

Question

Determine whether the function is increasing, decreasing, or constant. For each function check your answers with a graph or table:

Each number is divided by $(-1)$ .

00:00 Is the function increasing, decreasing, or constant?

00:03 Let's draw the function graph

00:11 Let's substitute X values and find the corresponding Y values

00:28 Now let's substitute negative X values to check the left side of the graph

00:35 We can see that the graph is always decreasing

00:39 And this is the solution to the question

The function is:

$f(x)=\frac{x}{-1}$

Let's start by assuming that x equals 0:

$f(0)=\frac{0}{-1}=0$

Now let's assume that x equals 1:

$f(1)=\frac{1}{-1}=-1$

Now let's assume that x equals 2:

$f(-1)=\frac{-1}{-1}=1$

Let's plot all the points on the function graph:

We see that we got a decreasing function.

Decreasing