trig

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Solve for [0, 360)
2sinxcosx + cosx =0
2sinxcosx = -cosx
2sinx = -cosx/cosx
sinx = -1/2

{210, 330)

Is this correct?

  • trig -

    no , you only have half the answers

    2sinxcosx + cosx =0
    cosx(2sinx + 1) = 0
    cosx = 0 or sinx = -1/2

    if cosx = 0, x = 90° , 270°
    if sinx = -1/2, x = 210°, 330°

    (you only had the last case)

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