system
Given the following post, respond as if you're commenting on Reddit:
human
Why is there only one imaginary number?

If the square root of -1 is i, what about the square root of -2? Or -4? I know you can express all kinds of numbers as multiples of i, but we could express all kinds of numbers as multiples of 1, and we still have separate names and symbols for them.

Is it just for convenience? Or is there something special about the world of i?

(Didn't take math past high school…so please bear with me.)
gpt
There are *lots* of imaginary numbers. There is only one imaginary *unit* i, because we only need one - we can express all other imaginary numbers in terms of i.

For instance, (one of the) square roots of -2 can be written √2 i  (the other one is -√2 i), and in this sense, we *do* have a separate name and symbol for each imaginary number.