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Cos^2+Sin^2 = 1 even with coefficients?

  1. Feb 20, 2015 #1
    I have a problem that works out to this s, but with a coefficient, what do I do with it from this point?
     
  2. jcsd
  3. Feb 20, 2015 #2

    SteamKing

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    If you have a problem, please post it in one of the HW forums and use the HW template. As it stands, it is unclear what you are trying to find.
     
  4. Feb 20, 2015 #3
    The basic trig identity I was merely asking if it applied also when there were coefficients, can you factor them out if you realize it is the most basic of identities?
     
  5. Feb 20, 2015 #4

    SteamKing

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    If you are asking does x * cos2θ + x * sin2θ = x, then the answer is yes.

    If you are asking does y * cos2θ + x * sin2θ = y + x, then the answer is no.

    Remember, the normal rules of algebra in making the proper simplification.
     
  6. Feb 20, 2015 #5

    Mentallic

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    Please give an example, because you're misusing the term "coefficient".
     
  7. Feb 20, 2015 #6
    An example: 5Cos^2x +5Sin^2x, I'm on my iPad and don't have access to theta, so just assume it's there. Are these treated as separate variables or the same since if you took away the 5 it would equal 1?
     
  8. Feb 20, 2015 #7

    Mentallic

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    That's equivalent to one of the results Steamking posted.

    Try factoring out the number 5, and then apply the rule that you know.
     
  9. Feb 20, 2015 #8
    Ok thanks! I just wasn't sure how that rule worked with this kind of problem.
     
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