Giúp mình với ạ. ….

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Giúp mình với ạ. ….
giup-minh-voi-a

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Jezebel 4 years 2020-11-13T19:22:02+00:00 2 Answers 54 views 0

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  1. Nem
    0
    2020-11-13T19:23:27+00:00
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    `ĐK: x ne π/2 + kπ`

    `PT`

    `=> cos² x – sin x.cos x = 1`

    `<=> -(1 – cos² x) – sin x.cos x = 0`

    `<=> – (sin² x + sin x.cos x) = 0`

    `<=> sin x(sin x + cos x) = 0`

    `<=>` \(\left[ \begin{array}{l}sin x = 0\\sin x + cos x = 0\end{array} \right.\) 

    `<=>` \(\left[ \begin{array}{l}x = kπ\\cos x = sin (-x)\end{array} \right.\) 

    `<=>` \(\left[ \begin{array}{l}x = kπ\\cos x = cos (\dfrac{\pi}{2} + x)\end{array} \right.\) 

    `<=>` \(\left[ \begin{array}{l}x = kπ\\x = -\dfrac{π}{2} – x + k2π\\x = \dfrac{π}{2} + x + k2π\end{array} \right.\) 

    `<=>` \(\left[ \begin{array}{l}x = kπ\\x = -\dfrac{π}{4} + kπ\end{array} \right.\) `( k ∈ ZZ)`

  2. Sigrid
    0
    2020-11-13T19:23:39+00:00
    Reply

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