Does i^(2/3) have two solutions
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Does i^(2/3) have two solutions

[From: ] [author: ] [Date: 13-08-22] [Hit: ]
infinity)-(-1)^(1/3)=(cos 180-isin180)^(1/3)=cos (180+360k)/3-isin(180+360k)/3k=0,1,......

r ( cos Θ + I sin Θ)

it is an alternative way for expressing a complex number called

"Polar Form for a Complex Number"

In fact, the polar form of a complex number and a concept
called DeMoivre's Theorem provide the usual tools we use
for figuring out the values complex bases raised to powers
named with real valued exponents.
powers.

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There is only one answer. For example a^(1/2) means the principal square root of a.

For this question Google gives the correct answer. Also, (-1)^(1/3) isn't -1. It is a complex number. Wolfram alpha gives the correct value of it and it is the same value as i^(2/3). So that is where the errors happened, once you start considering complex numbers, (-1)^(1/3) is no longer -1.

i = e^(iπ/2)

so i^(2/3) = (e^(iπ/2))^(2/3) = e^(iπ/3) = cos(π/3) + i*sin(π/3)

Note that I used radians since I'm used to using them while the other answers used degrees.

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I got the answer -1 so my belief their is only one solution.
It pretty much saying "(-1)^(1/3)^3 = -1, and (-1)^3 = -1."

https://www.google.com/#fp=92d015eca11a9…

The fact is (-1)^[1/(odd)] is always going to equal (-1) as long
the odd number is a whole number so (-infinity, infinity)

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(-1)^(1/3)
=(cos 180-isin180)^(1/3)

=cos (180+360k)/3-isin(180+360k)/3
k=0,1,2

so we get 3 different values

1)cos (180+360*0)/3-isin(180+360*0)/3=
=cos60+i sin60
=1/2+i sqrt 3/2


2)cos (180+360*1)/3-isin(180+360*1)/3=
=cos180+i sin180
=-1

3)cos (180+360*2)/3-isin(180+360*2)/3=
=cos300+i sin300=cos(360-60)+i sin(360-60)
=cos(-60)+isin(-60)

=1/2-i sqrt 3/2


ANSWER (i^2)^(1/3) = (-1)^(1/3) =
-1
1/2-i sqrt 3/2
1/2+i sqrt 3/2

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(-1)^1/3 is not equal to (-1)
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