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IMP IMP: Simplify!

  1. Oct 30, 2007 #1
    cos 4x + cos 3x/ sin4x - sin 3x
    Please somebody check this over!!

    The answer in the book is: cot (x/2)
     
  2. jcsd
  3. Oct 30, 2007 #2

    cristo

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    What do you mean by check this over? You've not done anything yet! Try expanding the trigonometric functions so that they end up in terms of cos(x) and sin(x).
     
  4. Oct 30, 2007 #3
    cos (4x+3x)
    ____________
    sin (4x+3x)
     
  5. Oct 30, 2007 #4
    or does the x have to be fatored out also?
    am i on right track
     
  6. Oct 30, 2007 #5

    cristo

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    No. Have you come across formulae, for general a and b, for sin(a+b) and cos(a+b)? If so, try writing cos(4x) as cos(3x+x).
     
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