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solve algebriaclly the equation y=2sin2x+1 for 0<_x_<180. when solved find the x coordinates of the roots.


    I am assuming you are trying to solve
    2sin2x+1 = 0
    sin 2x = -1/2
    (angle in standard position is 30º)
    the sine is negative in quadrants III and IV
    so x = 180+30 = 210
    or x = 360-x30 = 330

    Btw, don't shout!

  • Shouting! -

    When you type in all-caps, two things happen:
    **it's harder to read, and
    **it's the online equivalent to SHOUTING (considered rude behavior).

    Please just type in regular mode, not with the Caps Lock feature turned on. Thanks.

  • Correction -

    my last couple of lines should have been
    so 2x = 180+30 = 210
    or 2x = 360-x30 = 330

    so x = 105 or x = 165

    since the period of sin 2x is 180º
    two other solutions are 285º and 345º

    check: 2sin(2x345) + 1 = 0

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