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Homework Help: Single Trigonometric Functions ( trig identities)

  1. Mar 7, 2010 #1
    1. The problem statement, all variables and given/known data

    Cos^2x-Sin^2x/2 SinxCosx



    3. The attempt at a solution

    I changed cos^2x to 1- sin^2x

    which then the equation was 1- s sin^2x/2snxcosx and i have no idea how to make this a single trig. function
     
  2. jcsd
  3. Mar 7, 2010 #2

    rock.freak667

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    Homework Helper

    If you can't see it immediately then, what is 1-2sin2x the same as? What is 2sinxcosx the same as?

    Hint: Look up your double angle formulas.
     
  4. Mar 8, 2010 #3
    **Hint**

    [tex]sin(a+b)=sina \cdot cosb+sinb \cdot cosa[/tex]

    What if a and b where the same number...
     
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