ELI5: Explain Like I'm 5

Complex-valued function

Okay kiddo, so imagine you have a calculator that can do not just regular math, but also fancier math with make-believe numbers called "complex numbers". These numbers have two parts: a real part (like regular numbers you know) and an imaginary part (which is like a pretend number that doesn't really exist on its own, but helps us do the fancier math).

Now, let's say you have a rule book that tells you how to use your imaginary calculator to turn regular numbers into complex numbers. This rule book is called a "complex-valued function". It's like a recipe book for math.

When you put a regular number into this rule book, it tells you what complex number to get out. And if you put a different regular number in, you might get a different complex number out. It's kind of like baking cookies: if you follow the recipe and use different ingredients, you get different cookies.

So a complex-valued function is just a way for us to turn regular numbers into complex numbers using a special math recipe book. And we can use those complex numbers to do more complicated math problems that we couldn't do before. Pretty cool, huh?