View source for Square of i

==Theorem==
The following formula holds:
$$i^2=-1,$$
where $i$ denotes the [[imaginary number]].

==Proof==
From the definition of $i$,
$$i=\sqrt{-1}.$$
Squaring both sides shows
$$i^2 = \left( \sqrt{-1} \right)^2 = -1,$$
as was to be shown.

==References==

[[Category:Theorem]]
[[Category:Proven]]