(1+i)^(1/2)

4 min read Jun 16, 2024
(1+i)^(1/2)

Exploring the Square Root of (1 + i)

The expression (1 + i)^(1/2) represents the square root of the complex number (1 + i). Let's delve into finding this root and understanding its significance.

Complex Numbers and Roots

Complex numbers extend the real number system by introducing the imaginary unit 'i', where i² = -1. A complex number is expressed as a + bi, where 'a' and 'b' are real numbers.

Finding the square root of a complex number is akin to finding a number that, when multiplied by itself, results in the original complex number.

Finding the Square Root of (1 + i)

We can approach this problem in two main ways:

1. Algebraic Approach:

  • Assume the square root is of the form (x + yi), where x and y are real numbers.
  • Square this assumed root: (x + yi)² = (x² - y²) + (2xy)i
  • Equate the real and imaginary parts to the original number:
    • x² - y² = 1
    • 2xy = 1
  • Solve the system of equations: This yields two possible solutions:
    • x = √2 / 2, y = √2 / 2
    • x = -√2 / 2, y = -√2 / 2

Therefore, the square roots of (1 + i) are (√2 / 2 + √2 / 2 i) and (-√2 / 2 - √2 / 2 i).

2. Polar Form Approach:

  • Convert (1 + i) to polar form:
    • r = |1 + i| = √2
    • θ = arctan(1/1) = π/4
    • (1 + i) = √2 (cos(π/4) + i sin(π/4))
  • Apply De Moivre's Theorem: (r(cos θ + i sin θ))^(1/2) = √r (cos(θ/2 + kπ) + i sin(θ/2 + kπ)), where k = 0, 1.
  • Calculate the roots:
    • For k = 0: √2 (cos(π/8) + i sin(π/8))
    • For k = 1: √2 (cos(5π/8) + i sin(5π/8))

These solutions are equivalent to the ones found algebraically.

Conclusion

Finding the square root of (1 + i) demonstrates the elegance and power of complex number operations. The existence of two distinct square roots is a consequence of the fundamental nature of complex numbers and their representation in the complex plane. Understanding the square root of (1 + i) provides insight into the intricate world of complex numbers and their applications in various fields, including mathematics, physics, and engineering.

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