Generalizations
Euler's identity is also a special case of the more general identity that the nth roots of unity, for n > 1, add up to 0:
Euler's identity is the case where n = 2.
In another field of mathematics, by using quaternion exponentiation, one can show that a similar identity also applies to quaternions. Let {i, j, k} be the basis elements, then,
In general, given real an such that, then,
For octonions, with real an such that and the octonion basis elements {i1, i2,..., i7}, then,
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