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Thread: 2 quick sin/cos problems, solving for an angle

  1. December 15th 2008, 01:56 PM #1
    gobbajeezalus
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    2 quick sin/cos problems, solving for an angle



    Thanks!
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  2. December 16th 2008, 02:44 AM #2
    mathaddict
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    Re :

    (1) sinx=cos2x-1
    sinx=1-2sin^2x-1
    sinx=-2sin^2x
    sinx(2sinx+1)=0
    solve for sinx=0 and 2sinx+1=0

    (2) sinx+cosx=0]
    sinx=-cosx
    tanx=-1
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