Math(Trigonometry)

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kos^2 theta - sin^2 theta = 0.25

  • Math(Trigonometry) -

    the left side is a well know identity,
    cos^2 A - sin^2 A = cos 2A

    so we have:

    cos 2Ø = 1/4

    2Ø = 75.52° or 2Ø = 284.48°
    Ø = 37.76° , 142.24°, ...
    or
    Ø = .659 , 2.4825 ... in radians

    general solution in radians:
    .659 + kπ/2 , where k is an integer,
    2.4825 + kπ/2, where k is an integer.

    general solution in degrees:
    37.76° + 90k° , 142.24° + 90k°

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