[issue43830] (-1) ** 0.5 returns (6.123233995736766e-17+1j) instead of 1j

[Serhiy Storchaka]

Serhiy Storchaka <storchaka+cpython at gmail.com> added the comment:

It is the same "gotcha" as

>>> math.cos(math.pi/2)
6.123233995736766e-17

You can expect that cos(π/2) is exactly 0, but floating point value math.pi is only an approximation of the π number. The difference between math.pi and exact value of π leads to non-zero result of cos(math.pi/2).

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nosy: +serhiy.storchaka

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