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FP2 Complex numbers- exponential form

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Could someone possibly help with 11c and d? I'm not sure where to start.


Posted from TSR Mobile
Z=Rexp(i0)=R[cos0+isin0]
Z^2=(R[cos0+isin0])^2=R^2[cos20+isin20]
You can prove that using either expansion and trig relations or De Moivre's Theorem.
Start from there.
(edited 9 years ago)
Original post by Nuclear Ghost
Z=Rexp(i0)=R[cos0+isin0]
Z^2=(R[cos0+isin0])^2=R^2[cos20+isin20]
You can prove that using either expansion and trig relations or De Moivre's Theorem.
Start from there.


Okay, I've managed to get that, what now?
We haven't done De Moivre's theorem yet.


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Original post by Mutleybm1996
Okay, I've managed to get that, what now?
We haven't done De Moivre's theorem yet.


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1 is real, equate that to the real part of the complex number.
Original post by Mutleybm1996
Okay, I've managed to get that, what now?
We haven't done De Moivre's theorem yet.


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then just square z to get r^2e^2i(theta)
Original post by Ilovemaths96
then just square z to get r^2e^2i(theta)

My bad. :colondollar:
Original post by Nuclear Ghost
My bad. :colondollar:

lol
Original post by Ilovemaths96
then just square z to get r^2e^2i(theta)


Yep, I was playing around with it and got that, it was just trying to get from there to the (2cos0)e^i0 in the answer.


Posted from TSR Mobile
Original post by Nuclear Ghost
My bad. :colondollar:


Please See above ^


Posted from TSR Mobile
(edited 9 years ago)

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