My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum


Reply
 
LinkBack Thread Tools Display Modes
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
Bula is offline  
 
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).
mathman is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
complex, numbers, question



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Complex Numbers question (de Moivres) carl17 Algebra 2 October 26th, 2013 10:55 AM
Insane complex numbers question OriaG Algebra 16 August 27th, 2012 02:20 PM
Complex Numbers Question PLEASE HELP dylan182 Complex Analysis 4 December 16th, 2010 06:05 AM
Complex numbers question TsAmE Complex Analysis 11 November 17th, 2010 04:49 AM
Insane complex numbers question OriaG Calculus 16 December 31st, 1969 04:00 PM





Copyright © 2019 My Math Forum. All rights reserved.