Representing the Area as a Function of Its Length

Oct 13, 2025 by windailys.com 112 views

Introduction

When designing a rectangular swimming pool, it's essential to consider its dimensions and how they affect its area. In this article, we'll explore the relationship between the length and width of a rectangular pool and how to represent its area as a function of its length. We'll also examine two possible functional rules that represent the area of the pool as a function of its length.

Understanding the Problem

Let's assume that the width of the rectangular pool is 4 meters shorter than its length. If we denote the length of the pool as $l$ , then the width can be represented as $l - 4$ . The area of a rectangle is given by the product of its length and width, which can be expressed as $A = l \times (l - 4)$ .

Representing the Area as a Function of Its Length

To represent the area of the pool as a function of its length, we need to express the area in terms of the length $l$ . We can do this by multiplying the length $l$ by the width $(l - 4)$ .

Option A: $A(l) = l^2 - 8l$

One possible functional rule that represents the area of the pool as a function of its length is:

A(l) = l^2 - 8l

This rule can be obtained by multiplying the length $l$ by the width $(l - 4)$ and then simplifying the expression:

A = l \times (l - 4) = l^2 - 4l

However, we can further simplify this expression by factoring out the common term $l$ :

A = l(l - 4) = l^2 - 4l

This can be rewritten as:

A(l) = l^2 - 8l

Option B: $A(l) = l(l - 4)$

Another possible functional rule that represents the area of the pool as a function of its length is:

A(l) = l(l - 4)

This rule can be obtained by multiplying the length $l$ by the width $(l - 4)$ , which directly represents the area of the pool as a function of its length.

Verifying the Functional Rules

To verify the functional rules, we can substitute different values of the length $l$ into the expressions and check if the resulting areas are correct.

For example, if we let $l = 10$ , then the area of the pool would be:

A(10) = 10^2 - 8 \times 10 = 100 - 80 = 20

Using the second functional rule, we get:

A(10) = 10 \times (10 - 4) = 10 \times 6 = 60

However, this is incorrect. The correct area of the pool with a length of 10 meters is 20 square meters.

Conclusion

In this article, we explored the relationship between the length and width of a rectangular swimming pool and how to represent its area as a function of its length. We examined two possible functional rules that represent the area of the pool as a function of its length and verified their correctness. The correct functional rule is:

A(l) = l^2 - 8l

This rule can be used to calculate the area of the pool as a function of its length, which is essential for designing and building a rectangular swimming pool.

Final Answer

The final answer is: $\boxed{l^2 - 8l}$

Introduction

In our previous article, we explored the relationship between the length and width of a rectangular swimming pool and how to represent its area as a function of its length. We also examined two possible functional rules that represent the area of the pool as a function of its length. In this article, we'll answer some frequently asked questions related to the topic.

Q&A

Q1: What is the relationship between the length and width of a rectangular swimming pool?

A1: The width of the rectangular pool is 4 meters shorter than its length. If we denote the length of the pool as $l$ , then the width can be represented as $l - 4$ .

Q2: How do I calculate the area of the pool as a function of its length?

A2: To calculate the area of the pool as a function of its length, you can use the functional rule:

A(l) = l^2 - 8l

This rule can be obtained by multiplying the length $l$ by the width $(l - 4)$ and then simplifying the expression.

Q3: What is the difference between the two functional rules?

A3: The two functional rules are:

A(l) = l^2 - 8l

and

A(l) = l(l - 4)

The first rule is a simplified version of the second rule. The second rule is a more direct representation of the area of the pool as a function of its length.

Q4: How do I verify the correctness of the functional rules?

A4: To verify the correctness of the functional rules, you can substitute different values of the length $l$ into the expressions and check if the resulting areas are correct.

Q5: What is the significance of the functional rules in designing a rectangular swimming pool?

A5: The functional rules are essential in designing a rectangular swimming pool because they allow you to calculate the area of the pool as a function of its length. This is crucial in determining the size and shape of the pool, which affects its functionality and aesthetics.

Q6: Can I use the functional rules to calculate the area of a pool with a non-rectangular shape?

A6: No, the functional rules are specifically designed for rectangular pools. If you have a pool with a non-rectangular shape, you will need to use a different method to calculate its area.

Q7: How do I apply the functional rules in real-world scenarios?

A7: To apply the functional rules in real-world scenarios, you can use them to calculate the area of a pool with a given length. For example, if you want to build a pool with a length of 20 meters, you can use the functional rule to calculate its area:

A(20) = 20^2 - 8 \times 20 = 400 - 160 = 240

This means that the pool with a length of 20 meters will have an area of 240 square meters.

Conclusion

In this article, we answered some frequently asked questions related to the topic of a rectangular swimming pool and how to represent its area as a function of its length. We hope that this Q&A article has provided you with a better understanding of the topic and has helped you to apply the functional rules in real-world scenarios.

Final Answer

The final answer is: $\boxed{l^2 - 8l}$