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Homework Help: Find (x)

  1. Feb 28, 2005 #1
    hey ....


    find (x) ...
    (sin x )^6 + (cos x) ^6 = 5/6 ( (sin x)^4 + (cos x)^4)

    cheers
     
  2. jcsd
  3. Feb 28, 2005 #2
    x= 22.5
    .. I think
     
    Last edited: Feb 28, 2005
  4. Feb 28, 2005 #3

    dextercioby

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    There's the same problem posted in the "Brain Teasers" Section where i've given the correct answers...

    Daniel.
     
  5. Feb 28, 2005 #4

    HallsofIvy

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    If a problem involving trig functions does not specifically involve angle measured in degrees, x must be in "radians".

    x= pi/8 is correct.
     
  6. Feb 28, 2005 #5
    How do you solve such a problem? (Involving both functions)
     
  7. Mar 1, 2005 #6

    dextercioby

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    Use that:[tex] \sin^{2}x=1-\cos^{2}x [/tex] and the fact that the powers in the equation are even...:wink:

    Daniel.
     
  8. Mar 1, 2005 #7

    Zurtex

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    Erm, I think if you play around with it a bit you should be able to reduce it to :

    [tex]\cos 4x = 0[/tex]
     
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