four roots

Mat · 2007-05-01 18:08:15

Hi

I need some help on this complex number question.

Find the four roots of the equation z^4 = -1.
answer in form of a + jb where a and b are real.

Thanks

luca-deltodesco · 2007-05-01 18:25:15

this one is quite simple to solve, it is simply a quadratic in terms of z²

by the s and t subscripts, i mean that you can have them in any combination, one is not dependant on the other, in otherwords:

mathsyperson · 2007-05-01 22:29:07

That's interesting, I've never seen that notation before. Do the s and t mean anything or are they just arbitrary distinguishing symbols?

mat · 2007-05-02 00:21:18

Thanks for your reply.

how did u get

luca-deltodesco · 2007-05-02 02:21:51

mathsyperson wrote:

That's interesting, I've never seen that notation before. Do the s and t mean anything or are they just arbitrary distinguishing symbols?

they don't mean anything, its just to distinguish that they are not related, im not sure if its a proper notation, but ive seen it used before, and i often use it in this case.

for the 1/√2 i got that from typing it into google im not sure how you work it out, i havn't covered complex numbers yet in my studies, im guessing its one of those things you're just meant to learn, the same way you learn sin30° = 0.5, or sin45° = 1/sqrt(2) etc

Stanley_Marsh · 2007-05-02 02:41:55

Last edited by Stanley_Marsh (2007-05-02 02:43:03)

Math Is Fun Forum

#1 2007-05-01 18:08:15

four roots

#2 2007-05-01 18:25:15

Re: four roots

#3 2007-05-01 22:29:07

Re: four roots

#4 2007-05-02 00:21:18

Re: four roots

#5 2007-05-02 02:21:51

Re: four roots

#6 2007-05-02 02:41:55

Re: four roots

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