(1-i)^12

3 min read Jun 16, 2024
(1-i)^12

Demystifying (1-i)^12

This article explores the process of simplifying the complex expression (1 - i)^12.

Understanding Complex Numbers

Before diving into the calculation, let's understand the basics of complex numbers. A complex number is a number of the form a + bi, where 'a' and 'b' are real numbers and 'i' is the imaginary unit defined as the square root of -1 (i² = -1).

Utilizing De Moivre's Theorem

De Moivre's theorem offers a powerful tool for simplifying expressions involving complex numbers raised to powers. It states:

(cos θ + i sin θ)^n = cos(nθ) + i sin(nθ)

To apply this theorem, we need to convert our complex number (1 - i) into polar form.

Converting to Polar Form

  1. Magnitude: The magnitude or modulus of a complex number (a + bi) is calculated as: √(a² + b²). For (1 - i), the magnitude is √(1² + (-1)²) = √2.

  2. Angle: The angle (or argument) is determined using the arctangent function: θ = arctan(b/a). In our case, θ = arctan(-1/1) = -π/4. Since (1 - i) lies in the fourth quadrant, we need to add 2π to get the angle in the range of 0 to 2π: θ = 7π/4.

Therefore, the polar form of (1 - i) is √2(cos(7π/4) + i sin(7π/4)).

Applying De Moivre's Theorem

Now we can apply De Moivre's theorem:

(1 - i)^12 = [√2(cos(7π/4) + i sin(7π/4))]^12

= (√2)^12 [cos(12 * 7π/4) + i sin(12 * 7π/4)]

= 2^6 [cos(21π) + i sin(21π)]

= 64 [cos(π) + i sin(π)]

= 64 (-1 + 0i)

= -64

Final Result

Therefore, (1 - i)^12 simplifies to -64.

Featured Posts