(3-2i)^2

2 min read Jun 16, 2024
(3-2i)^2

Expanding (3 - 2i)^2

In mathematics, particularly in complex numbers, expanding expressions involving complex numbers often requires careful attention to the rules of multiplication and the properties of imaginary numbers. Let's explore the expansion of (3 - 2i)^2.

Understanding Complex Numbers

Before we delve into the expansion, let's briefly recall some key aspects of complex numbers:

  • Complex Number: 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 (i.e., i² = -1).

  • Squaring a Complex Number: When squaring a complex number, we apply the distributive property of multiplication: (a + bi)² = (a + bi)(a + bi).

Expanding (3 - 2i)²

Following the distributive property, we can expand (3 - 2i)² as follows:

(3 - 2i)² = (3 - 2i)(3 - 2i)

Expanding the product:

(3 - 2i)(3 - 2i) = 3(3 - 2i) - 2i(3 - 2i)

Applying the distributive property again:

9 - 6i - 6i + 4i²

Recall that i² = -1. Substituting:

9 - 6i - 6i + 4(-1)

Simplifying:

9 - 6i - 6i - 4

Combining real and imaginary terms:

(9 - 4) + (-6 - 6)i

Therefore, the expanded form of (3 - 2i)² is 5 - 12i.

Conclusion

Expanding (3 - 2i)² involves applying the distributive property of multiplication and utilizing the fundamental property of the imaginary unit (i² = -1). The result of the expansion is a new complex number, 5 - 12i, which represents the squared value of the original complex number.