What are Complex Numbers?
A **complex number** is a number that can be expressed in the form $a + bi$, where $a$ and $b$ are real numbers, and $i$ is the **imaginary unit**, defined as $i = \sqrt{-1}$.
In the expression $a + bi$:
- $a$ is the **real part**.
- $bi$ is the **imaginary part**.
Complex numbers extend the concept of real numbers to solve problems like finding the square root of a negative number, which is impossible in the real number system.
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Video: The Imaginary Plane!
Watch this video to visualize complex numbers on the Argand (or complex) plane! 🗺️
Practice Problems
Solve these problems based on the rules of complex numbers!
1) What is $(3 + 2i) + (1 - 4i)$?
2) What is $(5 - i) - (2 + 3i)$?
3) What is $(2i)^2$?
4) What is $i^4$?
⚡ Complex Numbers Speed Quiz
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