• cos2x = 1/2                0 < x < 30°
    cos2x = 60°

    Diketahui rumus cos x = cos α adalah
    x = α + k . 360 dan x = -α + k . 360, jadi

    2x = 60 + k . 360
    x = 30 + k . 180 (1)

    dan

    2x = -60 + k . 360
    x = -30 + k . 180 (2)

    (1) x = 30 + k . 180
    k = 0 = 30 + 0 . 180 = 30°

    (2) x = -30 + k .180
    k = 1 = -30 + 1 . 180 = 150°

    Jadi, HP = (30°,150°)


Pertanyaan Lainnya