Multiplying Complex Numbers: (-6i)(3i)
This article will guide you through the multiplication of two complex numbers, (-6i) and (3i).
Understanding Complex Numbers
Complex numbers are numbers that can be expressed in 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).
Multiplying (-6i)(3i)
-
Direct Multiplication: We simply multiply the coefficients and the imaginary units: (-6i)(3i) = (-6 * 3)(i * i)
-
Simplifying: -6 * 3 = -18 i * i = i²
-
Substituting i² = -1: -18 * i² = -18 * (-1)
-
Final Result: -18 * (-1) = 18
Therefore, the product of (-6i) and (3i) is 18.
Key Points
- Remember that the imaginary unit 'i' is treated like any other variable during multiplication.
- When multiplying complex numbers, remember to substitute i² with -1 to simplify the result.
- The final answer, 18, is a real number, demonstrating that the product of two imaginary numbers can be a real number.