ELI5: Explain Like I'm 5

Complex coordinate space

Okay kiddo, let's learn about complex coordinate space! Remember when we talked about the number line, where we can put numbers in order from left to right? In complex coordinate space, we have something similar called the complex plane.

Instead of just one line, the complex plane has two lines - a horizontal one called the real axis and a vertical one called the imaginary axis. Just like with the number line, we can put numbers on the complex plane to help us figure out where things are.

But with complex numbers, we have two parts - a real part and an imaginary part - which means we need two numbers to describe them. For example, if we have the complex number (2 + 3i), where i is the imaginary unit (kind of like another type of number), that means we want to go 2 spots to the right on the real axis (because the real part is 2) and 3 spots up on the imaginary axis (because the imaginary part is 3i).

So when we plot this on our complex plane, we go 2 spots to the right and 3 spots up, and we end up at the point (2, 3i). This point is like the home of our complex number (2 + 3i) on the complex plane - it's kind of like its address!

We can use this idea of points on the complex plane to do lots of cool things, like add and subtract complex numbers, find the distance between them, or even turn them around (kind of like spinning them like a top)!

So there you have it, kiddo - complex coordinate space is just like a map for complex numbers, where we use two numbers (real and imaginary parts) to find where they live on the complex plane. Pretty neat, huh?
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