Results 1 to 2 of 2

Math Help - complex algebra? series sum of sines or cosines

  1. #1
    Newbie
    Joined
    May 2012
    From
    Australia
    Posts
    5

    Question complex algebra? series sum of sines or cosines

    how do i calculate the sum of each of these series?

    sin(A) + sin(A+B) + sin(A+2B) + sin(A+3B) .... + sin(A+(n-1)B)
    cos(A) + cos(A+B) + cos(A+2B) + cos(A+3B) .... + cos(A+(n-1)B)

    please show step by step how to do it, not just the answer.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Jan 2008
    From
    UK
    Posts
    484
    Thanks
    65

    Re: complex algebra? series sum of sines or cosines

    Sum them together as C+i*S and write in exponential form. You'll get a GP. Find the sum. Separate the real and imaginary parts.

    I've not done the whole thing so I make no guarantees.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. law of sines and law of cosines
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: May 28th 2009, 05:26 AM
  2. Law of Sines and Cosines
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: November 23rd 2008, 04:49 AM
  3. LAw of sines and Law of Cosines
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: January 24th 2008, 10:12 AM
  4. Law of Sines/Cosines
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: December 8th 2007, 05:03 PM
  5. Law of Sines/Cosines
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: December 2nd 2007, 08:51 PM

Search Tags


/mathhelpforum @mathhelpforum