# Why is Euler's Identity stated the way it is?

Ok this is probably the most absurd question you'll ever read, but it came to my mind, and I cant shake it off. Eulers Identity states that: $e^{i\pi}+1=0$. So my ridiculous question is why was it stated this way? Why couldnt it have been $e^{i\pi}=-1$? Are there any reasons for this, or it could have been either of the two, but this one was chosen?

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Sorry I wasnt sure what to tag this at all, so I chose calculus. Please fix as needed. – maq Feb 13 '11 at 2:29
Well, I've seen it stated both ways. – Calle Feb 13 '11 at 2:44
It's just an aesthetic matter. I prefer the second one, though I think there's not much merit in this "identity" anyhow. – Yuval Filmus Feb 13 '11 at 2:55
I would call $e^{i\pi}+1=0$ an ${\it equation}$ and use the term ${\it identity}$ only for equations with a free variable in it, e.g. $e^{i\phi}=\cos(\phi) + i\sin(\phi)$. – Christian Blatter Feb 13 '11 at 11:18
@Yuval: "...there's not much merit..."? Really? – Mitch Feb 13 '11 at 15:29

The reason is to get just the $5$ "fundamental" numbers $\pi,e,i,0,1$ into one equation.