Each input must have exactly one output

Oct 13, 2025 by wbrum.org 123 views

Which of the Following Tables Could Represent a Function?

Understanding Functions in Mathematics

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 variables, where each input is associated with exactly one output. Functions are used to model real-world situations, such as the relationship between the amount of money spent and the number of items purchased.

Key Characteristics of Functions

For a relation to be considered a function, it must satisfy two key characteristics:

Each input must have exactly one output: This means that for every input value, there must be only one corresponding output value. If an input value has more than one output value, the relation is not a function.
The output value must depend only on the input value: This means that the output value must be determined solely by the input value, and not by any other factor.

Analyzing the Given Tables

We are given two tables to analyze:

A.$${ \begin{tabular}{|c|c|} \hline Input & Output \ \hline 1 & 0 \ 2 & 5 \ 3 & 2.5 \ 4 & 5 \ 5 & 8 \ \hline \end{tabular} }$$

B.$${ \begin{tabular}{|c|c|} \hline Input & Output \ \hline 1 & 0 \ 2 & 5 \ 3 & 2.5 \ 4 & 5 \ 5 & 8 \ 6 & 5 \ \hline \end{tabular} }$$

Table A: Does it Represent a Function?

Let's analyze Table A to see if it represents a function.

For each input value, there is only one corresponding output value. For example, the input value 1 has an output value of 0, and the input value 2 has an output value of 5.
The output value depends only on the input value. For example, the output value for input 2 is 5, and the output value for input 3 is 2.5, which depends only on the input values 2 and 3, respectively.

Based on these observations, Table A appears to represent a function.

Table B: Does it Represent a Function?

Now, let's analyze Table B to see if it represents a function.

For each input value, there is only one corresponding output value, except for the input value 4, which has two output values: 5 and 5.
The output value depends only on the input value, except for the input value 4, which has two output values: 5 and 5.

Based on these observations, Table B does not represent a function because the input value 4 has two output values.

Conclusion

In conclusion, Table A represents a function because each input value has exactly one output value, and the output value depends only on the input value. Table B does not represent a function because the input value 4 has two output values.

Key Takeaways

A function must satisfy two key characteristics: each input must have exactly one output, and the output value must depend only on the input value.
A relation is not a function if an input value has more than one output value.
A relation is not a function if the output value depends on any factor other than the input value.

Real-World Applications of Functions

Functions are used to model real-world situations, such as:

The relationship between the amount of money spent and the number of items purchased.
The relationship between the temperature and the amount of water evaporated.
The relationship between the amount of fertilizer applied and the yield of a crop.

Examples of Functions in Real-Life

A recipe for baking a cake is a function that takes the amount of ingredients as input and produces the cake as output.
A formula for calculating the area of a rectangle is a function that takes the length and width as input and produces the area as output.
A formula for calculating the interest on a loan is a function that takes the principal amount, interest rate, and time as input and produces the interest as output.

Conclusion

In conclusion, functions are an essential concept in mathematics that describe a relationship between variables. A function must satisfy two key characteristics: each input must have exactly one output, and the output value must depend only on the input value. Table A represents a function, while Table B does not. Functions are used to model real-world situations and have many real-life applications.
Q&A: Functions in Mathematics

Understanding Functions in Mathematics

In our previous article, we discussed the concept of functions in mathematics and analyzed two tables to determine which one represents a function. In this article, we will answer some frequently asked questions about functions in mathematics.

Q: What is a function in mathematics?

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 variables, where each input is associated with exactly one output.

Q: What are the key characteristics of a function?

A: A function must satisfy two key characteristics:

Each input must have exactly one output: This means that for every input value, there must be only one corresponding output value.
The output value must depend only on the input value: This means that the output value must be determined solely by the input value, and not by any other factor.

Q: How do I determine if a relation is a function?

A: To determine if a relation is a function, you can use the following steps:

Check if each input has exactly one output: If an input value has more than one output value, the relation is not a function.
Check if the output value depends only on the input value: If the output value depends on any factor other than the input value, the relation is not a function.

Q: What are some examples of functions in real-life?

A: Functions are used to model real-world situations, such as:

The relationship between the amount of money spent and the number of items purchased.
The relationship between the temperature and the amount of water evaporated.
The relationship between the amount of fertilizer applied and the yield of a crop.

Some examples of functions in real-life include:

A recipe for baking a cake is a function that takes the amount of ingredients as input and produces the cake as output.
A formula for calculating the area of a rectangle is a function that takes the length and width as input and produces the area as output.
A formula for calculating the interest on a loan is a function that takes the principal amount, interest rate, and time as input and produces the interest as output.

Q: How do I graph a function?

A: To graph a function, you can use the following steps:

Determine the domain and range: Identify the set of input values and the set of possible output values.
Plot the points: Plot the points on a coordinate plane, using the input values as the x-coordinates and the output values as the y-coordinates.
Draw the graph: Draw a smooth curve through the points to represent the function.

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

A: A function is a relation where each input value has exactly one output value, and the output value depends only on the input value. A relation is a set of ordered pairs, where each input value may have more than one output value.

Q: Can a function have multiple outputs?

A: No, a function cannot have multiple outputs. Each input value must have exactly one output value.

Q: Can a function have no outputs?

A: Yes, a function can have no outputs. For example, a function that takes the input value 0 and produces no output is still a function.

Conclusion

In conclusion, functions are an essential concept in mathematics that describe a relationship between variables. A function must satisfy two key characteristics: each input must have exactly one output, and the output value must depend only on the input value. We hope that this Q&A article has helped to clarify any questions you may have had about functions in mathematics.