division of complex numbers

The 6 Core Principles Behind Division of Complex Numbers

While the Division of Complex Numbers might initially seem intimidating, understanding the core principles behind this operation can simplify the process tremendously.

Complex numbers are, undoubtedly, an integral part of advanced mathematics, encompassing a realm beyond the familiar real numbers. One of the fundamental operations with complex numbers is division.

In this article, we delve into the six core principles that govern the division of complex numbers.

1. The Basic Structure of a Complex Number

Before diving into division, it’s essential to understand the structure of a complex number. Every complex number is expressed in the form (a + bi), where:

  • (a) is the real part
  • (b) is the imaginary part
  • (i) is the imaginary unit with the property [latex] i^2 = -1 [/latex].

For instance, in the number (3 + 4i), 3 is the real part, and 4 is the imaginary part.

2. The Role of the Conjugate

The conjugate of a complex number plays a crucial role in its division. The conjugate of [latex](a + bi) [/latex] is [latex](a – bi) [/latex]. Notice how only the sign of the imaginary part changes.

complex conjugates & division of complex numbers

Why is the conjugate important? Multiplying a complex number by its conjugate results in a real number, which is the key to the division process.

3. Division as Multiplication

The division of complex numbers is typically approached by transforming it into a multiplication problem. To divide two complex numbers, you multiply the numerator (the dividend) by the conjugate of the denominator (the divisor) and do the same for the denominator. This multiplication, especially in the denominator, converts the complex number into a real number.

4. Distributive Property and Multiplication

When multiplying complex numbers (as you would when dividing), remember to apply the distributive property. Consider:
[latex] (a + bi) \times (c + di) [/latex]

You’ll distribute each part of the first number to each part of the second number. This multiplication will involve both real and imaginary terms and might involve the property [latex] i^2 = -1 [/latex]).

5. Simplifying the Result

Once you’ve executed the multiplication in the division process, you might end up with a complex number in the form:
[latex] \frac{e + fi}{g} [/latex]
Where (e), (f), and (g) are real numbers. The final step is to distribute the denominator, (g), to both the real and imaginary parts of the numerator. This gives the final result of the division.

6. Visual Representation on the Complex Plane

The complex plane, with its real and imaginary axes, offers a visual representation of complex numbers. When you divide two complex numbers, you’re essentially scaling and rotating them in this plane. Understanding this geometric interpretation can offer deeper insights into the division operation and the relationships between complex numbers.

Watch this video to see 3 cool ways in which complex numbers shape mathematics, literally!

I was mind blown when I first saw the patterns of fractals.

Example:
Let’s put these principles into action with a simple example:
[latex] \frac{3 + 4i}{1 + 2i} [/latex]

Step 1: Identify the conjugate of the denominator: [latex] (1 – 2i) [/latex].

Step 2: Multiply both the numerator and the denominator by this conjugate:
[latex] \frac{3 + 4i}{1 + 2i} \times \frac{1 – 2i}{1 – 2i} [/latex]

Step 3: Apply distributive property and multiplication:
Numerator: [latex] (3 + 4i) \times (1 – 2i) = 3 – 6i + 4i – 8i^2 = 3 – 2i + 8 = 11 – 2i [/latex]
Denominator: [latex](1 + 2i) \times (1 – 2i) = 1 – 2i + 2i – 4i^2 = 1 + 4 = 5 [/latex]

Step 4: Simplify the result:
[latex] \frac{11 – 2i}{5} = 2.2 – 0.4i [/latex]

Thus, the result of the division is (2.2 – 0.4i).

Watch this video for a better understanding of the division of 2 complex numbers.

https://youtu.be/ubPl2YFkW64

In Conclusion:

Dividing complex numbers might appear challenging at first glance, but with a grasp of the underlying principles, it becomes a systematic and manageable process. Familiarizing yourself with these core concepts will not only enable you to tackle complex division problems but also deepen your overall understanding of complex numbers and their intriguing world.