Example of a Partial Function

Oct 13, 2025 by wbrum.org 96 views

In mathematics, a function is a relation between a set of inputs, called the domain, and a set of possible outputs, called the range. It is a way of describing a relationship between two sets of values, where each input value corresponds to exactly one output value. In this article, we will explore which of the given options represents a function.

What is a Function?

A function is a relation between a set of inputs, called the domain, and a set of possible outputs, called the range. It is a way of describing a relationship between two sets of values, where each input value corresponds to exactly one output value. In other words, for every input value, there is only one corresponding output value.

Option A: A Set of Ordered Pairs

Option A is a set of ordered pairs: $\{(0,1),(3,2),(-8,3),(-7,2),(3,4)\}$ . This set represents a relation between two sets of values, where each ordered pair corresponds to a specific input-output pair.

However, upon closer inspection, we can see that there are two ordered pairs with the same input value, $x=3$ . Specifically, the ordered pairs $(3,2)$ and $(3,4)$ both have the same input value, $x=3$ . This means that there are two different output values, $y=2$ and $y=4$ , corresponding to the same input value, $x=3$ .

Since a function requires that each input value corresponds to exactly one output value, this set of ordered pairs does not represent a function.

Option B: A Set of Ordered Pairs

Option B is also a set of ordered pairs: $\{(0,1),(3,2),(-8,3),(-7,2),(3,4)\}$ . This set is identical to Option A, and for the same reasons, it does not represent a function.

Option C: A Table of Values

Option C is a table of values: $${ \begin{tabular}{|c|c|c|c|c|c|} \hline x & -5 & -1 & 9 & 8 & -1 \ \hline y & 1 & 7 & 23 & 17 & 1 \ \hline \end{tabular} }$$. This table represents a relation between two sets of values, where each input value corresponds to a specific output value.

However, upon closer inspection, we can see that there are two input values, $x=-1$ and $x=9$ , that correspond to the same output value, $y=1$ . This means that there are two different input values, $x=-1$ and $x=9$ , that correspond to the same output value, $y=1$ .

Since a function requires that each input value corresponds to exactly one output value, this table of values does not represent a function.

Option D: A Set of Ordered Pairs

Option D is a set of ordered pairs: $\{(0,1),(3,2),(-8,3),(-7,2),(3,4)\}$ . This set is identical to Options A and B, and for the same reasons, it does not represent a function.

Conclusion

In conclusion, none of the given options represent a function. A function requires that each input value corresponds to exactly one output value, and all of the given options fail to meet this requirement.

What is a Relation?

A relation is a set of ordered pairs that describes a relationship between two sets of values. It is a way of describing a relationship between two sets of values, where each ordered pair corresponds to a specific input-output pair.

Types of Relations

There are several types of relations, including:

Functions: A relation where each input value corresponds to exactly one output value.
Non-Functions: A relation where each input value corresponds to more than one output value.
Partial Functions: A relation where each input value corresponds to at most one output value.

Example of a Function

A simple example of a function is the set of ordered pairs $\{(1,2),(2,4),(3,6)\}$ . In this example, each input value corresponds to exactly one output value, making it a function.

Example of a Non-Function

A simple example of a non-function is the set of ordered pairs $\{(1,2),(2,4),(1,6)\}$ . In this example, the input value $x=1$ corresponds to two different output values, $y=2$ and $y=6$ , making it a non-function.

Example of a Partial Function

A simple example of a partial function is the set of ordered pairs $\{(1,2),(2,4),(3,6)\}$ . In this example, each input value corresponds to at most one output value, making it a partial function.

Conclusion

Q: What is a function?

A: A function is a relation between a set of inputs, called the domain, and a set of possible outputs, called the range. It is a way of describing a relationship between two sets of values, where each input value corresponds to exactly one output value.

Q: What are the characteristics of a function?

A: The characteristics of a function include:

Each input value corresponds to exactly one output value: This means that for every input value, there is only one corresponding output value.
The output value is determined by the input value: This means that the output value is a function of the input value.
The function is a relation between the domain and the range: This means that the function is a way of describing a relationship between the domain and the range.

Q: What is the difference between a function and a non-function?

A: The main difference between a function and a non-function is that a function has a one-to-one correspondence between the input values and the output values, while a non-function has a many-to-one correspondence between the input values and the output values.

Q: What is the difference between a function and a partial function?

A: The main difference between a function and a partial function is that a function has a one-to-one correspondence between the input values and the output values, while a partial function has a one-to-one correspondence between the input values and the output values, but the function may not be defined for all input values.

Q: Can a function have multiple output values for the same input value?

A: No, a function cannot have multiple output values for the same input value. This is because a function is defined as a relation where each input value corresponds to exactly one output value.

Q: Can a function have no output value for a given input value?

A: Yes, a function can have no output value for a given input value. This is because a function is defined as a relation where each input value corresponds to at most one output value.

Q: Can a function have multiple input values that correspond to the same output value?

A: No, a function cannot have multiple input values that correspond to the same output value. This is because a function is defined as a relation where each input value corresponds to exactly one output value.

Q: What is the domain of a function?

A: The domain of a function is the set of all input values for which the function is defined.

Q: What is the range of a function?

A: The range of a function is the set of all output values that the function can produce.

Q: Can a function have an empty domain?

A: Yes, a function can have an empty domain. This means that the function is not defined for any input values.

Q: Can a function have an empty range?

A: Yes, a function can have an empty range. This means that the function produces no output values.

Q: What is the difference between a function and a relation?

A: The main difference between a function and a relation is that a function has a one-to-one correspondence between the input values and the output values, while a relation may have a many-to-one correspondence between the input values and the output values.

Q: Can a relation be a function?

A: Yes, a relation can be a function if it has a one-to-one correspondence between the input values and the output values.

Q: Can a function be a relation?

A: Yes, a function can be a relation if it has a one-to-one correspondence between the input values and the output values.

Conclusion

In conclusion, a function is a relation between a set of inputs, called the domain, and a set of possible outputs, called the range. It is a way of describing a relationship between two sets of values, where each input value corresponds to exactly one output value. A function has several characteristics, including a one-to-one correspondence between the input values and the output values, and the output value is determined by the input value.