Last updated on May 26th, 2025
If a number is multiplied by the same number, the result is a square. The inverse of the square is a square root. The concept of square roots, including complex numbers, is used in fields like engineering, physics, and mathematics. Here, we will discuss the square root of -180.
The square root is the inverse of the square of a number. However, the square root of a negative number involves complex numbers. The square root of -180 is expressed using the imaginary unit 'i'. It is written as √-180 = √180 * i. The value of √180 is approximately 13.416, so √-180 = 13.416i, which is a complex number.
Finding the square root of a negative number requires the introduction of the imaginary unit 'i', where i is defined as √-1. The process involves finding the square root of the positive counterpart first. Let us now learn the following methods:
1. Express the square root of a negative number using i.
2. Calculate the square root of the positive number.
3. Combine the results to express the full square root.
To express the square root using the prime factorization method, we first find the prime factors of the positive part of the number.
Step 1: Finding the prime factors of 180 Breaking it down, we get 2 x 2 x 3 x 3 x 5: 2² x 3² x 5
Step 2: Now we found the prime factors of 180. We express √180 as √(2² x 3² x 5) = 6√5.
Step 3: Since the square root involves a negative number, we multiply by i. Thus, √-180 = 6√5 * i.
The long division method can be used to find the square root of the positive counterpart, √180, with more precision. However, since -180 is negative, the final result will be multiplied by i.
Step 1: Group the numbers from right to left. For 180, there's no need for grouping as it's a three-digit number.
Step 2: Find n such that n² ≤ 1. The closest is 1 since 1² = 1.
Step 3: Bring down the next digits, making the next number 80.
Step 4: Double the current quotient (1) to get 2, making 20n the new divisor.
Step 5: Find the largest n such that 20n * n ≤ 80. This gives n = 4, so the divisor becomes 24.
Step 6: Continue this process to find more decimal places, eventually finding √180 ≈ 13.416.
Step 7: Multiply by i to account for the negative number, so √-180 = 13.416i.
The approximation method can help in estimating the square root by considering nearby perfect squares.
Step 1: Identify the perfect squares around 180. The perfect squares are 169 (13²) and 196 (14²).
Step 2: √180 lies between 13 and 14. Calculate the approximate decimal using linear interpolation: (180 - 169) / (196 - 169) ≈ 0.407
Step 3: Thus, √180 ≈ 13 + 0.407 = 13.407. Multiply this by i to get √-180 ≈ 13.407i.
Students often make mistakes when dealing with negative square roots, such as forgetting to include the imaginary unit 'i'. Let's explore some common errors and how to avoid them.
If Max has a complex number 3 + √-180, what is its modulus?
The modulus is approximately 13.76.
The modulus of a complex number a + bi is √(a² + b²). For 3 + 13.416i, the modulus is √(3² + 13.416²) ≈ 13.76.
A rectangle has a length of √-180 and a width of 5. What is its area?
The area is a complex number: 67.08i square units.
Area = length × width.
Length = √-180 = 13.416i, Width = 5.
Area = 13.416i × 5 = 67.08i square units.
Calculate 2 × √-180.
The result is approximately 26.832i.
First, find √-180 ≈ 13.416i.
Then, multiply by 2: 2 × 13.416i = 26.832i.
What is the square root of (-180 + 20) in terms of i?
The square root is approximately 12.806i.
First, find the sum: -180 + 20 = -160. Then, √-160 = √160 * i ≈ 12.806i.
Find the hypotenuse of a right triangle with legs of 12 and √-180.
The hypotenuse is a complex number: approximately 18.44i.
Hypotenuse, h = √(12² + (13.416i)²).
Since (13.416i)² is negative, the hypotenuse will involve complex arithmetic: h ≈ 18.44i.
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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