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Last updated on May 26th, 2025

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Square Root of -49

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If a number is multiplied by itself, the result is a square. The inverse of the square is a square root. The square root is used in various fields such as vehicle design, finance, etc. Here, we will discuss the square root of -49.

Square Root of -49 for Global Students
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What is the Square Root of -49?

The square root is the inverse of the square of a number. Since -49 is a negative number, its square root involves imaginary numbers. The square root of -49 is expressed as √(-49) and can be written using the imaginary unit 'i', where i = √(-1). Thus, the square root of -49 is 7i.

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Finding the Square Root of -49

The square root of a negative number involves imaginary numbers. The square root of -49 is not a real number, and the methods used for real numbers do not apply directly. Instead, we utilize the concept of imaginary numbers.

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Square Root of -49 Using Imaginary Numbers

When dealing with the square root of negative numbers, we use the imaginary unit 'i', defined as √(-1). For -49, we have:

 

Step 1: Recognize -49 as 49 multiplied by -1.

 

Step 2: Apply the property of square roots: √(-49) = √(49) * √(-1).

 

Step 3: Calculate √(49), which is 7, and use the definition of i: √(-1) = i.

 

Step 4: Combine these results to get 7i.

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Understanding Imaginary Numbers

Imaginary numbers are used to represent the square roots of negative numbers. The imaginary unit 'i' is the cornerstone of this concept, allowing us to calculate and understand values like √(-49). Imaginary numbers extend the real number system to form the complex number system.

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Applications of Imaginary Numbers

Imaginary numbers have applications in various fields, such as engineering, physics, and computer science. They are essential in solving equations that do not have real solutions and are used in signal processing, control systems, and complex analysis.

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Common Mistakes and How to Avoid Them in the Square Root of -49

Understanding the square root of negative numbers can be tricky. Students often make mistakes such as ignoring the imaginary unit 'i' or misapplying real number methods. Let's explore some common errors and how to avoid them.

Mistake 1

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Ignoring the Imaginary Unit 'i'

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When finding the square root of a negative number, failing to include the imaginary unit 'i' can lead to incorrect solutions. Remember that √(-49) = 7i, not just 7.

Mistake 2

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Confusing Real and Imaginary Roots

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Students may confuse the square roots of negative numbers with those of positive numbers. Emphasize that negative numbers require the use of 'i' and result in imaginary roots.

Mistake 3

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Using Real Number Methods Incorrectly

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Attempting to apply real number methods, such as prime factorization or long division, to negative numbers is incorrect. These methods only apply to non-negative numbers.

Mistake 4

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Overlooking the Properties of 'i'

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Understanding the properties of 'i', such as i² = -1, is crucial. Mistakes occur when these properties are overlooked, leading to incorrect calculations.

Mistake 5

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Confusing Complex and Imaginary Numbers

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Imaginary numbers are part of complex numbers, but they are not the same. Complex numbers consist of both real and imaginary parts, while imaginary numbers have no real component.

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Square Root of -49 Examples

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Problem 1

What is the product of the square root of -49 and 3?

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21i

Explanation

The square root of -49 is 7i.

To find the product with 3, multiply 7i by 3: 7i × 3 = 21i.

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Problem 2

Calculate the square of the square root of -49.

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-49

Explanation

The square root of -49 is 7i.

The square of 7i is (7i)² = 49 × i² = 49 × (-1) = -49.

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Problem 3

If x = √(-49), what is x²?

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-49

Explanation

Since x = √(-49) = 7i, then x² = (7i)² = 49 × i² = 49 × (-1) = -49.

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Problem 4

Find the result of multiplying √(-49) by 2i.

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-14

Explanation

The square root of -49 is 7i.

Multiplying by 2i gives: 7i × 2i = 14i² = 14 × (-1) = -14.

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Problem 5

What is the square root of -49 plus the square root of 49?

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0

Explanation

The square root of -49 is 7i, and the square root of 49 is 7.

Adding these gives 7i + 7.

However, since they are not like terms, the expression remains as 7 + 7i.

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FAQ on Square Root of -49

1.What is √(-49) in its simplest form?

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2.What does the imaginary unit 'i' represent?

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3.Can the square root of a negative number be real?

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4.How do imaginary numbers relate to complex numbers?

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5.Why are imaginary numbers important?

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Important Glossaries for the Square Root of -49

  • Square root: A square root is the inverse of squaring a number. For negative numbers, the square root involves imaginary numbers.
     
  • Imaginary number: An imaginary number is a number that can be expressed as a real number multiplied by the imaginary unit 'i', where i = √(-1).
     
  • Complex number: A complex number includes both real and imaginary parts, represented as a + bi, where a and b are real numbers.
     
  • Imaginary unit: The imaginary unit 'i' is defined as the square root of -1 and is fundamental in complex number calculations.
     
  • Negative number: A negative number is a real number that is less than zero and requires imaginary units when finding square roots.
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Jaskaran Singh Saluja

About the Author

Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.

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Fun Fact

: He loves to play the quiz with kids through algebra to make kids love it.

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