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Math Help - [Solved] Trig Equation

  1. #1
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    [Solved] Trig Equation

    I can't figure out the following question:

    Solve the equation for 0 less than or equal than x less than or equal than 2pi:

    16cos^2x - 4cosx + 1 = 0

    Aside (using "y" instead of "cos" to visualize):

    16y^2 - 4y + 1 = 0
    4y (4y - 1) + 1 = 0 or (4cosx[4cosx - 1] + 1 = 0)


    Nevermind, I just realized you can't solve this equation
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Macleef View Post
    I can't figure out the following question:

    Solve the equation for 0 less than or equal than x less than or equal than 2pi:

    16cos^2x - 4cosx + 1 = 0

    Aside (using "y" instead of "cos" to visualize):

    16y^2 - 4y + 1 = 0
    4y (4y - 1) + 1 = 0 or (4cosx[4cosx - 1] + 1 = 0)


    Nevermind, I just realized you can't solve this equation
    you can mark it unsolved you know.

    that's not how you would solve a quadratic like this. use the quadratic formula.

    (this quadratic has no real roots by the way (the discriminant is negative). check to make sure you have the correct question)
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