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March 27th, 2013, 02:16 AM  #1 
Newbie Joined: Mar 2013 Posts: 1 Thanks: 0  complex numbers question
Hey, Could somebody please help me with this question? A) solve z^5= 1 in polar form I did that and found z=1, z=cis 2pi/5, z=cis 4pi/5, z= cis 2pi/5 The rest of the question perplexed me though; B) describe how the solutions from A are related to the solutions of y^2=( 5+5^(1/2))/8 and y^2=( 5 5^(1/2))/8 I don't see the relation :/ C) use the information from A and B to write the exact value of sin 2pi/5. I know how to find the exact value but not using the information in this question. Any help would be greatly appreciated. Thank you 
March 27th, 2013, 12:48 PM  #2 
Global Moderator Joined: May 2007 Posts: 6,768 Thanks: 699  Re: complex numbers question
Can't help with B or C. For A you left out one solution. z = cis(4?/5).


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