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Math Help - Quadrant solutions

  1. #1
    Senior Member
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    Quadrant solutions

    2 sin 4x + sqrt3 = 0

    Rewritten:
    2 sin 4x = - sqrt3

    sqrt3 can be a positive or negative number so there are solutions in all quadrants? My book says only the third and fourth. I don't need any further work done.
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  2. #2
    MHF Contributor
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    Quote Originally Posted by Stuck Man View Post
    2 sin 4x + sqrt3 = 0

    Rewritten:
    2 sin 4x = - sqrt3

    sqrt3 can be a positive or negative number so there are solutions in all quadrants? My book says only the third and fourth. I don't need any further work done.
    hi

    your book is right . \sin 4x=-\frac{\sqrt{3}}{2} and sin is negative in teh 3rd and 4th quadrant .

    Note that x=\sqrt{4}\Rightarrow x=2 but if x^2=4\Rightarrow x=\pm 2
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  3. #3
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    I didn't know that. I've been making that mistake for a while now.
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