Giai pt sau 1) sin2x-cosx=0

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Giai pt sau
1) sin2x-cosx=0

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Amity 4 years 2020-11-09T14:30:28+00:00 2 Answers 75 views 0

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  1. King
    0
    2020-11-09T14:31:44+00:00
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    Đáp án:

     

    Giải thích các bước giải:

     

    giai-pt-sau-1-sin2-cos-0

  2. Dau
    0
    2020-11-09T14:32:16+00:00
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    $\sin2x-\cos x=0$

    $\Leftrightarrow 2\sin x\cos x-\cos x=0$

    $\Leftrightarrow \cos x(2\sin x-1)=0$

    $+) \cos x=0\Leftrightarrow x=\dfrac{\pi}{2}+k\pi$

    $+) \sin x=0,5\Leftrightarrow x=\dfrac{\pi}{6}+k2\pi$ hoặc $x=\dfrac{5\pi}{6}+k2\pi$

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )