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 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 #2

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 #3

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 #4

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 #5

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 #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

Is the given graph a function?

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Video Solution

Step-by-Step Solution

To determine if the given graph represents a function, we use the vertical line test: if any vertical line intersects the graph at more than one point, the graph is not a function.

Let's apply this test to the graph:

  • Examine different sections of the graph by drawing imaginary vertical lines.
  • Look for intersections where more than one point exists on the vertical line.

Upon examining the graph, we observe that there are several vertical lines that intersect the graph at multiple points, particularly in areas with loops or overlapping curves. This indicates that at those x x -values, there are multiple y y -values corresponding to them.

Since there exist such vertical lines, according to the vertical line test, the graph does not represent a function.

Thus, the solution to this problem is that the given graph is not a function.

Answer

No

Exercise #8

Is the given graph a function?

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Video Solution

Step-by-Step Solution

To determine if the graph in question represents a function, we'll employ the Vertical Line Test. This test helps to ascertain whether each input value from the domain (x-values) is connected to a unique output value (y-values).

  • According to the Vertical Line Test, a graph represents a function if no vertical line can intersect the graph at more than one point.
  • In the provided diagram, the graph is a straight line.
  • Visual inspection shows that any vertical line drawn at any point along the x-axis intersects the line exactly once.
  • This indicates that for each x-value, there is a unique corresponding y-value. Therefore, the relationship depicted by the graph meets the criteria for a function.

Thus, the given graph correctly characterizes a function.
Therefore, the solution to the problem is Yes.

Answer

Yes

Exercise #9

Is the given graph a function?

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Video Solution

Step-by-Step Solution

To determine if the graph is a function, we will use the Vertical Line Test.

The Vertical Line Test states that a graph represents a function if and only if no vertical line intersects the graph at more than one point.

Let's apply this test to the given graph, where a horizontal line is drawn. This line represents the function the graph should be verified against.

  • Step 1: Conceptualize vertical lines passing through different x-values across the domain of the graph.
  • Step 2: Observe if any of these vertical lines intersect the graph at more than one point.

Upon inspection of the graph, we see that every vertical line intersects the graph at exactly one point.

This indicates that for every input (x-value), there is a unique output (y-value), fulfilling the criteria for the definition of a function.

Therefore, according to the Vertical Line Test, the given graph is indeed a function.

The correct choice is: Yes

Answer

Yes

Exercise #10

Determine whether the following table represents a constant function

XY-101247

Video Solution

Step-by-Step Solution

To determine if the table represents a constant function, we need to examine the Y-values corresponding to the X-values given in the table.

  • Step 1: Identify the given values from the table. The pairs are as follows: - For X=1X = -1, Y=2Y = 2 - For X=0X = 0, Y=4Y = 4 - For X=1X = 1, Y=7Y = 7
  • Step 2: Check if all Y-values are the same. Compare Y-values for each X-value:
  • - Y=2Y = 2 when X=1X = -1, - Y=4Y = 4 when X=0X = 0, - Y=7Y = 7 when X=1X = 1.

Since the Y-values (2, 4, and 7) are not the same, the function is not constant.

Thus, the table does not represent a constant function. The correct choice is: No.

Answer

No

Exercise #11

Is the given graph a function?

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Video Solution

Step-by-Step Solution

To determine whether the graph represents a function, we apply the Vertical Line Test. Here are the steps we follow:

  • Step 1: Visualize placing a vertical line across various parts of the graph.
  • Step 2: Check if the vertical line intersects the graph at more than one point at any given position.

Step 1: On evaluating the given graph carefully, there is a notable presence of a vertical line passing through multiple y-values. Specifically, the vertical line goes from y=3 y = -3 to y=3 y = 3 at x=3 x = 3 .

Step 2: Since this vertical line at x=3 x = 3 intersects the graph at an infinite number of points, it fails the Vertical Line Test.

Therefore, the graph does not represent a function. According to our analysis and the Vertical Line Test, the correct answer is No.

Answer

No

Exercise #12

Determine whether the following table represents a function

XY-226101416111621

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given pairs of (X,Y)(X, Y).
  • Step 2: Verify that each XX maps to exactly one YY.
  • Step 3: Conclude whether the table represents a function.

Now, let's work through each step:
Step 1: The pairs given are: (2,1)(-2, 1), (2,6)(2, 6), (6,11)(6, 11), (10,16)(10, 16), (14,21)(14, 21).

Step 2: For each input value XX, we check its corresponding output YY:

  • X=2X = -2 maps to Y=1Y = 1
  • X=2X = 2 maps to Y=6Y = 6
  • X=6X = 6 maps to Y=11Y = 11
  • X=10X = 10 maps to Y=16Y = 16
  • X=14X = 14 maps to Y=21Y = 21
None of the values of XX is associated with more than one different YY value.

Step 3: Since each XX value has exactly one corresponding YY value, the table represents a function.

Yes

Answer

Yes

Exercise #13

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 #14

Determine whether the following table represents a linear function

XY-126123

Video Solution

Step-by-Step Solution

To determine if the table represents a linear function, we need to check if the slope between each consecutive pair of points is constant.
Using the slope formula m=y2y1x2x1 m = \frac{y_2 - y_1}{x_2 - x_1} , we calculate:

  • Between points (1,1)(-1, 1) and (2,2)(2, 2):
    m=212(1)=13 m = \frac{2 - 1}{2 - (-1)} = \frac{1}{3}
  • Between points (2,2)(2, 2) and (6,3)(6, 3):
    m=3262=14 m = \frac{3 - 2}{6 - 2} = \frac{1}{4}

Since the slopes are not equal (1314 \frac{1}{3} \neq \frac{1}{4} ), the function is not linear.

Thus, the table does not represent a linear function.

Answer

No

Exercise #15

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

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Video Solution

Step-by-Step Solution

To determine the correct equation from the given choices, we observe that the graph represents a horizontal line, positioned at y=3 y = 3 . A horizontal line is defined by a constant y-value because it does not change as x changes. Thus, the line corresponds to the equation y=3 y = 3 , indicating this is the correct equation from the choices provided.

Therefore, the solution to the problem is y=3 y = 3 .

Answer

y=3 y=3