Last updated on May 26th, 2025
If a number is multiplied by itself, the result is a square. The inverse of the square is a square root. The concept of square roots extends to complex numbers when dealing with negative values under the square root. Here, we will discuss the square root of -100.
The square root of a negative number involves complex numbers because there is no real number whose square is negative. The square root of -100 is expressed in terms of the imaginary unit 'i', where i² = -1. Therefore, the square root of -100 can be expressed as ±10i.
Complex numbers include a real part and an imaginary part. They are usually expressed in the form a + bi, where 'a' is the real part and 'bi' is the imaginary part. The imaginary unit 'i' is defined as the square root of -1. Thus, for -100, its square roots are 10i and -10i, which are purely imaginary numbers.
The exponential form helps to express complex numbers. Since i is the square root of -1, the square root of -100 can be written as: (-100)^(1/2) = 100^(1/2) * (-1)^(1/2) = 10 * i = 10i. Thus, the square root of -100 is ±10i in exponential form.
Complex numbers can be represented graphically on the complex plane, where the x-axis represents the real part and the y-axis represents the imaginary part. The square roots of -100, which are ±10i, lie on the imaginary axis, 10 units above and below the origin.
Complex numbers are used in various fields such as engineering, quantum physics, applied mathematics, and signal processing. They are particularly useful in problems involving oscillations, waves, and alternating current (AC) circuits. The concept of imaginary numbers allows for solutions to equations that do not have real solutions.
Students often make mistakes when working with the square root of negative numbers, especially when transitioning from real to complex numbers. Let's explore a few common errors and how to avoid them.
What is the square of the square root of -100?
The square of the square root of -100 is -100.
The square root of -100 is ±10i.
Squaring this gives: (10i)² = 100 * i² = 100 * (-1) = -100.
Similarly, (-10i)² = 100 * (-1) = -100.
Thus, squaring the square root returns the original number, -100.
If z = √-100, what is the modulus of z?
The modulus of z is 10.
The modulus of a complex number a + bi is √(a² + b²). For z = ±10i, the modulus is: |10i| = √(0² + 10²) = √100 = 10.
Calculate the sum of (3 + √-100) and (5 - √-100).
The sum is 8.
Let √-100 = 10i. Then (3 + 10i) + (5 - 10i) = 3 + 5 + 10i - 10i = 8.
The imaginary parts cancel out, leaving the real part as the sum.
What is the result of multiplying √-100 by √-1?
The result is -10.
Let √-100 = 10i.
Then multiplying by √-1 (which is i) gives: 10i * i = 10i² = 10(-1) = -10.
If f(x) = √-100, for what value of x is f(x) defined?
f(x) is defined for all x, as it is a constant function.
The function f(x) = √-100 is a constant function with a value of ±10i, indicating it is defined for any input x, as it doesn't depend on x.
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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