system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 What are imaginary numbers? When we started getting into that stuff in school I got completely lost.
gpt
You know what a square root is, right? It's the number X that, when you multiply it by itself, gives you the number Y. X^2 = Y.

Now, you also know that whether you multiply two negative numbers together or two positive numbers together, you get a positive number at the other end of the math. Therefore, you can't take the square root of a negative number, because there's no way for you to get a negative result.

But *imagine* for a second that you could. Define a number *i* such that *i*^2 = -1, and you have the *imaginary unit,* the basis of all complex numbers.