Forgetting to include the negative sign

Oct 13, 2025 by wbrum.org 43 views

Introduction

In mathematics, the square root of a number is a value that, when multiplied by itself, gives the original number. The square root of a number can be either positive or negative. In this article, we will evaluate the expression $-\sqrt{4}$ and determine its solution.

Understanding the Square Root

The square root of a number is denoted by the symbol $\sqrt{}$ . For example, $\sqrt{16}$ is equal to 4 because 4 multiplied by 4 gives 16. Similarly, $\sqrt{9}$ is equal to 3 because 3 multiplied by 3 gives 9.

Evaluating $-\sqrt{4}$

To evaluate $-\sqrt{4}$ , we need to understand the concept of negative numbers and square roots. The negative sign in front of the square root indicates that we are looking for the negative square root of 4.

The Negative Square Root

The negative square root of a number is equal to the negative of the positive square root of that number. In other words, if $\sqrt{a}$ is equal to $b$ , then $-\sqrt{a}$ is equal to $-b$ .

Evaluating $-\sqrt{4}$ Using the Definition of Negative Square Root

Using the definition of negative square root, we can rewrite $-\sqrt{4}$ as $- \times \sqrt{4}$ . Since $\sqrt{4}$ is equal to 2, we can substitute this value into the expression to get $- \times 2$ .

Simplifying the Expression

To simplify the expression $- \times 2$ , we can multiply the negative sign by 2. This gives us a final answer of $-2$ .

Conclusion

Examples and Applications

The concept of negative square roots has many practical applications in mathematics and science. For example, in physics, the negative square root of a number can be used to represent the velocity of an object in a particular direction.

Real-World Applications

The concept of negative square roots is also used in many real-world applications, such as:

Navigation: In navigation, the negative square root of a number can be used to represent the direction of a ship or a plane.
Engineering: In engineering, the negative square root of a number can be used to represent the velocity of a moving object.
Computer Science: In computer science, the negative square root of a number can be used to represent the direction of a vector in a particular coordinate system.

Common Mistakes

When evaluating expressions involving negative square roots, it is common to make mistakes. Some common mistakes include:

Forgetting to include the negative sign: When evaluating expressions involving negative square roots, it is easy to forget to include the negative sign. This can result in an incorrect answer.
Not understanding the concept of negative square roots: Not understanding the concept of negative square roots can lead to confusion and incorrect answers.

Tips and Tricks

To avoid making mistakes when evaluating expressions involving negative square roots, here are some tips and tricks:

Read the problem carefully: Before starting to evaluate an expression involving a negative square root, read the problem carefully to make sure you understand what is being asked.
Use the definition of negative square root: When evaluating expressions involving negative square roots, use the definition of negative square root to simplify the expression.
Check your answer: After evaluating an expression involving a negative square root, check your answer to make sure it is correct.

Conclusion

In conclusion, the solution to the expression $-\sqrt{4}$ is $-2$ . This is because the negative sign in front of the square root indicates that we are looking for the negative square root of 4, which is equal to $-2$ . By understanding the concept of negative square roots and using the definition of negative square root, we can simplify expressions involving negative square roots and arrive at the correct answer.

Introduction

In our previous article, we evaluated the expression $-\sqrt{4}$ and determined its solution to be $-2$ . In this article, we will answer some frequently asked questions about evaluating expressions involving negative square roots.

Q: What is the difference between a positive square root and a negative square root?

A: The positive square root of a number is a value that, when multiplied by itself, gives the original number. The negative square root of a number is equal to the negative of the positive square root of that number.

Q: How do I evaluate an expression involving a negative square root?

A: To evaluate an expression involving a negative square root, use the definition of negative square root. This means that if $\sqrt{a}$ is equal to $b$ , then $-\sqrt{a}$ is equal to $-b$ .

Q: What is the solution to the expression $-\sqrt{9}$ ?

A: The solution to the expression $-\sqrt{9}$ is $-3$ . This is because the negative sign in front of the square root indicates that we are looking for the negative square root of 9, which is equal to $-3$ .

Q: Can I use a calculator to evaluate expressions involving negative square roots?

A: Yes, you can use a calculator to evaluate expressions involving negative square roots. However, make sure to understand the concept of negative square roots and use the definition of negative square root to simplify the expression.

Q: How do I simplify an expression involving a negative square root?

A: To simplify an expression involving a negative square root, use the definition of negative square root. This means that if $\sqrt{a}$ is equal to $b$ , then $-\sqrt{a}$ is equal to $-b$ .

Q: What is the solution to the expression $-\sqrt{16}$ ?

A: The solution to the expression $-\sqrt{16}$ is $-4$ . This is because the negative sign in front of the square root indicates that we are looking for the negative square root of 16, which is equal to $-4$ .

Q: Can I use a calculator to check my answer?

A: Yes, you can use a calculator to check your answer. However, make sure to understand the concept of negative square roots and use the definition of negative square root to simplify the expression.

Q: How do I know if my answer is correct?

A: To know if your answer is correct, check your work and make sure you have used the definition of negative square root to simplify the expression.

Q: What is the solution to the expression $-\sqrt{25}$ ?

A: The solution to the expression $-\sqrt{25}$ is $-5$ . This is because the negative sign in front of the square root indicates that we are looking for the negative square root of 25, which is equal to $-5$ .

Conclusion

In conclusion, evaluating expressions involving negative square roots requires an understanding of the concept of negative square roots and the definition of negative square root. By using the definition of negative square root, we can simplify expressions involving negative square roots and arrive at the correct answer.