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[Further Maths FP2] Roots of unity

Studying nth roots of unity at the moment, and I'm stuck with finding the complex solutions to the following:

16z^4 = (z-1)^4

I get to:

2z = i(z-1)

But don't know where to go from there.
Reply 1
Original post by Haza100
Studying nth roots of unity at the moment, and I'm stuck with finding the complex solutions to the following:

16z^4 = (z-1)^4

I get to:

2z = i(z-1)

But don't know where to go from there.


post your workings are there are more than 1 method for doing this
Reply 2
Original post by TeeEm
post your workings are there are more than 1 method for doing this


16z4=(z1)416z^4 = (z-1)^4

2z=14(z1)2z = \sqrt[4]{1} (z-1)

14=1,1,i,i\sqrt[4]{1} = 1, -1, i, -i

Solving for real solutions gives z=1/3 and z=-1

Can't seem to rearrange for z to get complex solutions, I must be being stupid... all help appreciated.
Reply 3
Original post by Haza100
16z4=(z1)416z^4 = (z-1)^4

2z=14(z1)2z = \sqrt[4]{1} (z-1)

14=1,1,i,i\sqrt[4]{1} = 1, -1, i, -i

Solving for real solutions gives z=1/3 and z=-1

Can't seem to rearrange for z to get complex solutions, I must be being stupid... all help appreciated.


one approach using elementary techniques you can find on page 35 on this link
http://www.madasmaths.com/archive/maths_booklets/further_topics/various/complex_numbers_part_1_exam_questions.pdf
Reply 4
Original post by TeeEm
one approach using elementary techniques you can find on page 35 on this link
http://www.madasmaths.com/archive/maths_booklets/further_topics/various/complex_numbers_part_1_exam_questions.pdf


Thanks mate, that helped a lot. Haven't done much math recently so stupidly couldn't see how to rearrange it for z.

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