sin 3x + cos 2x = 0

Question

sin 3x + cos 2x = 0

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Latifah 6 years 2020-11-28T05:35:21+00:00 2 Answers 77 views 0

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    0
    2020-11-28T05:36:44+00:00

    Đáp án:

     

    Giải thích các bước giải:

     

    sin-3-cos-2-0

    0
    2020-11-28T05:36:46+00:00

    `sin(3x) + cos(2x) = 0`

    `⇔cos(2x) = -sin(3x) `

    `⇔cos(2x)=(π/2+3x)`

    `⇔`\(\left[ \begin{array}{l}2x=\dfrac{π}{2}+3x+k2π\\2x=π-\dfrac{π}{2}-3x+k2π\end{array} \right.\)`(k∈Z)`

    `⇔`\(\left[ \begin{array}{l}x=-\dfrac{π}{2}-k2π\\x=\dfrac{π}{10}+\dfrac{k2π}{10}\end{array} \right.\)`(k∈Z)`

     

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