math

smallest degree that satisfies 2cos^2x-3cosx=2

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asked by joe s
  1. 2cos^2x-3cosx=2
    2cos^2x - 3cosx - 2 = 0
    (2cosx + 1)(cosx - 2) = 0
    cosx = -1/2 or cosx = 2, the last part is not possible

    cosx = -1/2, so the smallest angle is in quadrant II
    x = 120° or 2π/3 rads , assuming you wanted the smallest positive angle

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    posted by Reiny

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