Mik cần gấp giúp mik với ạ

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Mik cần gấp giúp mik với ạ
mik-can-gap-giup-mik-voi-a

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Neala 4 years 2020-10-16T17:35:52+00:00 1 Answers 102 views 0

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    2020-10-16T17:37:51+00:00
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    4) $\tan x = \tan\alpha$ $\left(x, \alpha \ne \dfrac{\pi}{2} + n\pi\right)$

    $\Leftrightarrow x = \alpha +k\pi\quad (k\in\Bbb Z)$

    1a) $\sin x = \dfrac{\sqrt3}{2}$

    $\Leftrightarrow \left[\begin{array}{l}x = \dfrac{\pi}{3} + k2\pi\\x = \dfrac{2\pi}{3} + k2\pi\end{array}\right.\quad (k\in\Bbb Z)$

    b) $2\cos x – 1 = 0$

    $\Leftrightarrow \cos x = \dfrac{1}{2}$

    $\Leftrightarrow x = \pm \dfrac{\pi}{3} + k2\pi\quad (k\in\Bbb Z)$

    c) $2\sin^2x – 3\sin x + 1 = 0$

    $\Leftrightarrow \left[\begin{array}{l}\sin x = 1\\\sin x = \dfrac{1}{2}\end{array}\right.$

    $\Leftrightarrow \left[\begin{array}{l}x = k2\pi\\x = \dfrac{\pi}{6} + k2\pi\\x = \dfrac{5\pi}{6} + k2\pi\end{array}\right.\quad (k\in\Bbb Z)$

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