Ways to represent a function

Functions can be represented in several ways, each providing a unique perspective on the relationship between inputs and outputs. Here are the primary methods:

Algebraic Representation

Representation using an equation of XX and YY, such as f(x)=2x+3f(x) = 2x + 3, showing how the output depends on the input.

Graphical representation

A visual representation on a coordinate plane, like using a graph, plotting on the XX and YY axis, where the function's behavior and trends (e.g., linear, quadratic) can be observed.

Tabular representation

A table of values that pairs inputs (xx) with corresponding outputs (yy) for a quick reference of specific points.

Verbal representation

A written explanation describing the relationship between variables, such as “The output is twice the input plus three.” Expressing the relationship between XX and YY using words.

Function notation

Functions can be written using different notations, such as Y=Y= or f(x)=f(x)=, both of which represent the output in terms of the input.

Practice Representations of Functions

Examples with solutions for Representations of Functions

Exercise #1

Determine whether the given graph is a function?

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Video Solution

Step-by-Step Solution

It is important to remember that a function is an equation that assigns to each element in domain X one and only one element in range Y

We should note that for every X value found on the graph, there is one and only one corresponding Y value.

Therefore, the graph is indeed a function.

Answer

Yes

Exercise #2

Is the given graph a function?

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Video Solution

Step-by-Step Solution

It is important to remember that a function is an equation that assigns to each element in domain X one and only one element in range Y

Let's note that in the graph:

f(0)=2,f(0)=2 f(0)=2,f(0)=-2

In other words, there are two values for the same number.

Therefore, the graph is not a function.

Answer

No

Exercise #3

Determine whether the following table represents a function

XY-1015811

Video Solution

Step-by-Step Solution

It is important to remember that a constant function describes a situation where as the X value increases, the function value (Y) remains constant.

In the table, we can observe that there is a constant change in X values, meaning an increase of 1, and a constant change in Y values, meaning an increase of 3

Therefore, according to the rule, the table describes a function.

Answer

Yes

Exercise #4

Determine whether the following table represents a constant function:

XY02468-3-3-3-3-3

Video Solution

Step-by-Step Solution

It is important to remember that a constant function describes a situation where, as the X value increases, the Y value remains constant.

In the table, we can see that there is a constant change in the X values, specifically an increase of 2, while the Y value remains constant.

Therefore, the table does indeed describe a constant function.

Answer

Yes, it does

Exercise #5

Determine whether the data in the following table represent a constant function

XY012348

Video Solution

Step-by-Step Solution

It is important to remember that a constant function describes a situation where as the X value increases, the function value (Y) remains constant.

In the table, we can observe that there is a constant change in X values, meaning an increase of 1, and a non-constant change in Y values - sometimes increasing by 1 and sometimes by 4

Therefore, according to the rule, the table does not describe a function

Answer

No

Exercise #6

Does the graph below represent a function?

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Video Solution

Step-by-Step Solution

It is important to remember that a function is an equation that assigns to each value in domain x x only one value in range y y .

Since we can see that for every x x value found on the graph there is only one correspondingy y value, the graph is indeed a function.

Answer

Yes

Exercise #7

Which of the following equations corresponds to the function represented in the graph?

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Video Solution

Step-by-Step Solution

Let's use the below formula in order to find the slope:

m=y2y1x2x1 m=\frac{y_2-y_1}{x_2-x_1}

We begin by inserting the known data from the graph into the formula:

(0,2),(2,0) (0,-2),(-2,0)

m=200(2)= m=\frac{-2-0}{0-(-2)}=

20+2= \frac{-2}{0+2}=

22=1 \frac{-2}{2}=-1

We then substitute the point and slope into the line equation:

y=mx+b y=mx+b

0=1×(2)+b 0=-1\times(-2)+b

0=2+b 0=2+b

Lastly we combine the like terms:

0+(2)=b 0+(-2)=b

2=b -2=b

Therefore, the equation will be:

y=x2 y=-x-2

Answer

y=x2 y=-x-2

Exercise #8

Which of the following equations corresponds to the function represented in the table?

XY-3-1135246810

Video Solution

Step-by-Step Solution

We will begin by using the formula for finding slope:

m=y2y1x2x1 m=\frac{y_2-y_1}{x_2-x_1}

First let's take the points:

(1,4),(3,8) (-1,4),(3,8)

m=843(1)= m=\frac{8-4}{3-(-1)}=

843+1= \frac{8-4}{3+1}=

44=1 \frac{4}{4}=1

Next we'll substitute the point and slope into the line equation:

y=mx+b y=mx+b

8=1×3+b 8=1\times3+b

8=3+b 8=3+b

Lastly we'll combine like terms:

83=b 8-3=b

5=b 5=b

Therefore, the equation will be:

y=x+5 y=x+5

Answer

y=x+5 y=x+5

Exercise #9

Determine whether the following table represents a function

XY-101247

Video Solution

Answer

No

Exercise #10

Determine whether the following table represents a function

XY-226101416111621

Video Solution

Answer

Yes

Exercise #11

Is the given graph a function?

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Video Solution

Answer

No

Exercise #12

Is the given graph a function?

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Video Solution

Answer

Yes

Exercise #13

Is the given graph a function?

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Video Solution

Answer

No

Exercise #14

Is the given graph a function?

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Video Solution

Answer

Yes

Exercise #15

Which of the following equations corresponds to the function represented in the table?

XY-125811246810

Video Solution

Answer

y=23x+223 y=\frac{2}{3}x+2\frac{2}{3}