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Trigonometry identity sin(pi)cos(wpi)+cos(pi)sin(wpi)

  1. Feb 18, 2013 #1
    1. The problem statement, all variables and given/known data

    Hi guys, How can sin(∏)cos(ω∏)-cos(∏)sin(ω∏) = sin(ω∏)? please guide me trigonometry identity to apply with this?

    2. Relevant equations



    3. The attempt at a solution


    sin_x_pi.jpg
     
  2. jcsd
  3. Feb 18, 2013 #2

    Dick

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    sin(pi)=0, cos(pi)=(-1). So, of course, sin(∏)cos(ω∏)-cos(∏)sin(ω∏) = sin(ω∏). I'm not sure what that has to do with what follows.
     
  4. Feb 18, 2013 #3
    Ohhh :shy: Just been thinking about using trig identity, thank you Dick !
     
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