Mathematicians answer this please

Hi guys,
So I just stumbled across a video and this talked about Euler’s Identity. How e^(Pie x i) + 1 = 0
I didn’t really understand much of how this was proved but when I went into the comment section and someone asked how is it possible to use two numbers which apparently never end that then give a answer of a natural number in this case 0
Someone answered Saying it’s not about the number itself like for example Pie And i, but it has something to do with a complex plane?
Well is there any way you could answer this for me? I mean if you know a number doesn’t end and you don’t even know the rest of the numbers how could you possibly be able to cancel that out with another imaginary number?
Well thank you then!

Its fairly easy to google and if youve seen a video/comments it would help to say which one and what youre covered ... but if you define / derive the imaginay exponential as
e^(ix) = cos(x) + i*sin(x)
then its just subbing x=pi and its clear. The imaginary exponential can be justified using the usual series expansions.

That’s true, i forgot to Google It, the video which I saw this on didn’t really explain it. They showed the first few letters of Pie and e, then simply went to saying that e^( Pie x i ) equals -1. i literally went straight to writing this Haha
But I see, maybe watching the video I’ll understand more
Thank you!

Proving it usually requires deriving the more general result so the imaginary exponential function mentioned in the previous, then
e^(i*pi) = cos(pi) + i*sin(pi) = -1
A related result is
i^i = e^(-pi/2) ~ 0.2
so an imaginary number raised to an imaginary power is real and related to e and pi.