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# De moivre theorem watch

1. Anyone wants to have a go at these questions? Will probably rep the first person with the correct answer.

Let z = 81j
find all values of Z^ (1/4) expressing your answers in the form re^j0 sorry 0 is theta.

Let z = sqrt3 - j
find z^6 in form x+yj note find argz as a multiple of pi

manifest
2. Remind me of De Moivre's Theorem please?

3. Notice that and
4. (Original post by AlphaNumeric)

Notice that and
For the second bit i got -64

the first bit i got pi/8, 5pi/8, -3pi/8 and -7pi/8 as the angles r is obviously 3
am i right?

mani
5. If z = 81 = , then , not 64
6. (Original post by AlphaNumeric)
If z = 81 = , then , not 64
you got me wrong. I was referring to the second question not the second bit of the question. I got r as 3 which was quite straightforward but I am not sure about the angles. pi/8, 5pi/8 ...

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Updated: October 8, 2006
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