Last updated on May 26th, 2025
When a number is squared, the result is a perfect square. The inverse operation is finding the square root. Square roots are used in various fields such as engineering, physics, and mathematics. Here, we will discuss the square root of -98.
The square root is the inverse operation of squaring a number. Since -98 is negative, it does not have a real number square root. The square root of -98 is expressed in terms of imaginary numbers. In radical form, it is expressed as √(-98), or equivalently as √98i, where i is the imaginary unit with the property that i² = -1. The value of √98 is approximately 9.899, so √(-98) = 9.899i.
Finding the square root of a negative number involves using the imaginary unit i. We express the square root of a negative number in terms of i and the positive part of the number. For √(-98), we first calculate the square root of 98, and then multiply by i:
1. Calculate √98.
2. Multiply the result by i.
The prime factorization method is used to simplify the square root of positive numbers. For negative numbers, we factor the positive part. Let’s see how 98 is broken down into its prime factors:
Step 1: Prime factorize 98. 98 = 2 × 7 × 7 = 2 × 7²
Step 2: Use the prime factors to simplify: √98 = √(2 × 7²) = 7√2
Step 3: Multiply by i: The square root of -98 is 7√2i.
The long division method is not applicable to negative numbers directly for real square roots, but it can be used to approximate the square root of the positive part (98) before multiplying by i.
Step 1: Group digits of 98 from right to left as 98.
Step 2: Find an n such that n² is closest to 98. Here, n = 9 since 9² = 81.
Step 3: The approximate square root of 98 is 9.899.
Step 4: Multiply by i: √(-98) = 9.899i.
The approximation method can also be used for the positive part of -98.
Step 1: Find the closest perfect squares around 98. The closest perfect squares to 98 are 81 (9²) and 100 (10²).
Step 2: Estimate √98 using these perfect squares. √98 is approximately 9.899.
Step 3: Multiply by i to get the square root of -98: √(-98) = 9.899i.
Mistakes may occur when dealing with negative square roots, especially involving imaginary numbers. Here are a few common errors and how to avoid them.
What is the square root of -196?
The square root is 14i.
First, find the square root of 196, which is 14.
Since the original number is negative, we multiply by i, resulting in 14i.
Calculate the square root of -49.
7i
Find the square root of 49, which is 7.
Multiply by i for the negative square root: √(-49) = 7i.
What is the result of √(-16) * √(-4)?
-8
√(-16) = 4i and √(-4) = 2i.
Multiply: 4i * 2i = 8i².
Since i² = -1, the result is -8.
Find the product of √(-9) and √(-1).
3
√(-9) = 3i and √(-1) = i.
Multiply: 3i * i = 3i² = 3(-1) = -3.
If z = √(-64), what is the magnitude of z?
8
The magnitude of a complex number a + bi is √(a² + b²). Here, z = 8i, so the magnitude is √(0² + 8²) = √64 = 8.
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.
: He loves to play the quiz with kids through algebra to make kids love it.