- #1

chwala

Gold Member

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- Homework Statement:
- Kindly see attached...I just want to understand why for the case; ##(-1+i)^\frac {1}{3}## they divided by ##3## and not multiply ?

- Relevant Equations:
- Complex numbers

Kindly see attached...I just want to understand why for the case; ##(-1+i)^\frac {1}{3}## they divided by ##3## when working out the angles...

Am assuming they used;

##(\cos x + i \sin x)^n = \cos nx + i \sin nx## and here, we require ##n## to be positive integers...unless I am not getting it...sorry using phone to type ...I will put this into context later...

For ##z^5 = -32## No issue here...the steps ,that is division by ##5## is clear.

Am assuming they used;

##(\cos x + i \sin x)^n = \cos nx + i \sin nx## and here, we require ##n## to be positive integers...unless I am not getting it...sorry using phone to type ...I will put this into context later...

For ##z^5 = -32## No issue here...the steps ,that is division by ##5## is clear.