# What Is a Non Real Complex Number

What Is a Non-Real Complex Number?

Complex numbers are an essential part of mathematics, providing a way to represent both real and imaginary numbers in a single entity. In this article, we will explore the concept of non-real complex numbers, their properties, and their significance in various mathematical applications.

Definition and Representation:

A non-real complex number is a complex number that does not have a real part. In other words, it is purely imaginary. A complex number is typically represented in the form a + bi, where a is the real part, b is the imaginary part, and i is the imaginary unit (√-1). Non-real complex numbers, however, have a zero real part (a = 0) and can be written as bi.

For example, the number 3i is a non-real complex number, as it has no real part and is purely imaginary. Similarly, -2i, 7i, and πi are all non-real complex numbers.

Properties of Non-Real Complex Numbers:

Non-real complex numbers possess certain properties that distinguish them from real numbers and other types of complex numbers. Some of these properties include:

1. Imaginary Part Only: Non-real complex numbers have an imaginary part but lack a real part. They can be visualized as points on the imaginary axis of the complex plane.

2. Multiplication by i: Multiplying a non-real complex number by i results in a real number. For instance, multiplying 3i by i gives -3.

3. Conjugate Pair: Every non-real complex number has a conjugate, which is obtained by changing the sign of its imaginary part. For example, the conjugate of 4i is -4i.

4. Addition/Subtraction with Real Numbers: Non-real complex numbers can be added or subtracted with real numbers. The resulting complex number will have a non-zero imaginary part.

Significance and Applications:

Non-real complex numbers find applications in various fields of mathematics, science, and engineering. Here are a few instances where non-real complex numbers play a crucial role:

1. Electrical Engineering: In AC circuit analysis, non-real complex numbers are used to represent the impedance of different circuit elements. The imaginary part of the impedance represents the reactive component, which determines the phase relationship between voltage and current.

2. Quantum Mechanics: Non-real complex numbers are extensively used in quantum mechanics to represent wave functions. The imaginary part of a wave function corresponds to the probability amplitude, which determines the likelihood of finding a particle at a specific location.

3. Signal Processing: Non-real complex numbers are utilized in signal processing algorithms, such as Fourier transforms, to analyze and manipulate complex signals. The imaginary part represents the phase information of the signal.

FAQs:

Q: Are non-real complex numbers irrational?
A: No, non-real complex numbers are not classified as irrational numbers. Irrational numbers cannot be expressed as a fraction or a repeating decimal, whereas non-real complex numbers can be represented as a purely imaginary fraction.

Q: Can non-real complex numbers be plotted on a real number line?
A: No, non-real complex numbers cannot be plotted on a real number line as they lack a real part. They are represented on the imaginary axis of the complex plane.

Q: Can non-real complex numbers be multiplied by other non-real complex numbers?
A: Yes, non-real complex numbers can be multiplied by other non-real complex numbers. However, the product will always have a real part, unlike the multiplicand numbers.