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: 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

  2. jcsd
  3. Feb 18, 2013 #2


    User Avatar
    Science Advisor
    Homework Helper

    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 !
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook