Examples with solutions for Increasing and Decreasing Intervals of a Function: Finding Increasing or Decreasing Domains

Exercise #1

Determine in which domain the function is negative?

–0.5–0.5–0.50.50.50.51111.51.51.5222000

Video Solution

Step-by-Step Solution

Let's remember that a function is increasing if both X values and Y values are increasing simultaneously.

A function is decreasing if X values are increasing while Y values are decreasing simultaneously.

In the graph, we can see that in the domain x > 1 the function is decreasing, meaning the Y values are decreasing.

Answer

x > 1

Exercise #2

In what domain does the function increase?

–20–20–20–10–10–10101010202020–10–10–10101010000

Video Solution

Step-by-Step Solution

Let's remember that the function increases if the x x values and y y values increase simultaneously.

On the other hand, the function decreases if the x x values increase while the y y values decrease simultaneously.

In the given graph, we can see that the function increases in the domain where x > 0 ; in other words, where the y y values are increasing.

Answer

x > 0

Exercise #3

In what domain does the function increase?

000

Video Solution

Step-by-Step Solution

Let's remember that the function increases if the X values and Y values increase simultaneously.

On the other hand, the function decreases if the X values increase and the Y values decrease simultaneously.

In the given graph, we notice that the function increases in the domain where x < 0 , meaning the Y values are increasing.

Answer

x<0

Exercise #4

In what domain is the function increasing?

–5–5–5555101010151515–5–5–5555000

Video Solution

Step-by-Step Solution

Let's first remember that a function is increasing if both the X and Y values are increasing simultaneously.

Conversely, a function is decreasing if the X values are increasing while the Y values are decreasing simultaneously.

In the graph shown, we can see that the function is increasing in every domain and therefore the function is increasing for all values of X.

Answer

All values of x x

Exercise #5

In what interval is the function increasing?

Purple line: x=0.6 x=0.6

111222333111000

Video Solution

Step-by-Step Solution

Let's remember that a function is increasing if both X values and Y values are increasing simultaneously.

A function is decreasing if X values are increasing while Y values are decreasing simultaneously.

In the graph, we can see that in the domain x < 0.6 the function is increasing, meaning the Y values are increasing.

Answer

x<0.6

Exercise #6

In which interval does the function decrease?

Red line: x=0.65 x=0.65

111222333–1–1–1111000

Video Solution

Step-by-Step Solution

Remember that a function is increasing if both the x x values and the y y values are increasing simultaneously.

A function is decreasing if the x x values are increasing while the y y values are decreasing simultaneously.

In the graph we can see that the function is decreasing in all domains. In other words, it is decreasing for all x x .

Answer

All values of x x

Exercise #7

In what domain does the function increase?

Black line: x=1.1 x=1.1

–2–2–2222444666222000

Video Solution

Step-by-Step Solution

Remember that a function is increasing if the x x values and y y values are increasing simultaneously.

A function is decreasing if the X values are increasing and the Y values are decreasing simultaneously.

In the plotted graph, we can see that in the domain 1.1 > x > 0 the function is increasing—meaning the y y values are increasing.

Answer

1.1 > x > 0

Exercise #8

In which domain does the function increase?

Green line:
x=0.8 x=-0.8

–2–2–2222222000

Video Solution

Step-by-Step Solution

The function increases if X values and Y values increase simultaneously.
In this function, despite its unusual form, we can see that the function continues to increase according to the definition at all times,
and there is no stage where the function decreases.
Therefore, we can say that the function increases for all X, there is no X we can input where the function will be decreasing.

Answer

All values of x x

Exercise #9

In what domain does the function increase?

–10–10–10–5–5–5555101010151515202020–10–10–10–5–5–5555000

Video Solution

Step-by-Step Solution

Let's remember that the function increases if the X values and Y values increase simultaneously.

On the other hand, the function decreases if the X values increase and the Y values decrease simultaneously.

In the given graph, we notice that the function increases in the domain where 1 > x > -1 meaning the Y values are increasing.

Answer

1 > x > -1

Exercise #10

In what domain is the function decreasing?

–1–1–1111–1–1–1111000

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

In the given graph, we notice that the function decreases in two different places on the graph.

The first time it decreases in the domain where 0 > x > -1 and the second time it decreases in the domain where

x > 1

This means that in these domains, the Y values are decreasing.

Answer

0>x>-1,x>1

Exercise #11

In which domain does the function decrease?

x-210-1.58-0.560021353.5759

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where x < 0 X values increase and Y values decrease simultaneously.

Therefore, the function decreases in the domain where

x < 0

Answer

x<0

Exercise #12

In which domain does the function decrease?

f(x)x-210-1.58-160423353.57109

Video Solution

Step-by-Step Solution

Let's remember that a function is increasing if both X values and Y values are increasing simultaneously.

A function is decreasing if X values are increasing while Y values are decreasing simultaneously.

According to the value table, we can see that in the domain x < 2 , X values are increasing while Y values are decreasing simultaneously. Therefore, the function is decreasing in the domain x < 2

Answer

x<2

Exercise #13

In which domain does the function decrease?

f(x)x-24-110011721151671911

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where x < 0 X values increase and Y values decrease simultaneously.

Therefore, the function decreases in the domain where

x < 0

Answer

x<0

Exercise #14

In which domain does the function decrease?

f(x)x001223354352607-4

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where x > 3 X values increase and Y values decrease simultaneously.

Therefore, the function decreases in the domain where

x > 3

Answer

x>3

Exercise #15

In which domain is the function increasing?

x-1010-78-360425463.5789

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where 0 > x X values and Y values increase simultaneously.

Therefore, the function increases in the domain where

x > 0

Answer

x>0

Exercise #16

In which domain is the function increasing?

x-24-1100111.52305-78-9

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where 1.5 > x > 0 the X values and Y values increase simultaneously.

Therefore, the function increases in the domain where

1.5 > x > 0

Answer

1.5>x>0

Exercise #17

In which domain is the function increasing?

f(x)x-57-1.58-110014215343.5250

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where x < 2 the X values and Y values increase simultaneously.

Therefore, the function increases in the domain where

x < 2

Answer

x<2

Exercise #18

In which domain is the function increasing?

f(x)x-104-48-211010213-54-75-9

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where x < -2 the X values and Y values increase simultaneously.

Therefore, the function increases in the domain where

x < -2

Answer

x<-2

Exercise #19

In which domain is the function increasing?

f(x)x-24-1100112.52305-78-9

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where 2.5 > x > 0 the X values and Y values increase simultaneously.

Therefore, the function increases in the domain where

2.5 > x > 0

Answer

2.5>x>0

Exercise #20

In which domain is the function increasing?

f(x)x-44-1100116210014-78-9

Video Solution

Step-by-Step Solution

Let's remember that the function increases when X values and Y values increase simultaneously.

On the other hand, the function decreases when X values increase and Y values decrease simultaneously.

According to the given value table, we can see that in the domain where 10 > x > 0 the X values and Y values increase simultaneously.

Therefore, the function increases in the domain where

10 > x > 0

Answer

10 > x > 0