1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Fourier Series Representation of Signals (Proof)

  1. Jan 26, 2013 #1
    Hi guys,

    I was studying the proof below and just can't figure out the the first highlighted step leads to the second and I was wondering if you guys can help me to fill that in. (:

    fxylpkz.jpg

    Thank you so much for your help in advance guys!
     
  2. jcsd
  3. Jan 26, 2013 #2

    MathematicalPhysicist

    User Avatar
    Gold Member

    It follows from:

    cos(a+b)= cos(a)cos(b)-sin(a)sin(b)
     
  4. Jan 26, 2013 #3
    Thank you so much! :D
     
  5. Jan 26, 2013 #4
    -- it's okay, I for it. Really stupid question. hahaha ---
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook