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Câu hỏi: Tìm tập xác định D của hàm số $y=\tan \left( 2x+\dfrac{\pi }{3} \right)$.
A. $D=\mathbb{R}\backslash \left\{ \dfrac{\pi }{12}+k\dfrac{\pi }{2}|k\in \mathbb{Z} \right\}$.
B. $D=\mathbb{R}\backslash \left\{ \dfrac{\pi }{6}+k\pi |k\in \mathbb{Z} \right\}$.
C. $D=\mathbb{R}\backslash \left\{ \dfrac{\pi }{12}+k\pi |k\in \mathbb{Z} \right\}$.
D. $D=\mathbb{R}\backslash \left\{ -\dfrac{\pi }{6}+k\dfrac{\pi }{2}|k\in \mathbb{Z} \right\}$.
A. $D=\mathbb{R}\backslash \left\{ \dfrac{\pi }{12}+k\dfrac{\pi }{2}|k\in \mathbb{Z} \right\}$.
B. $D=\mathbb{R}\backslash \left\{ \dfrac{\pi }{6}+k\pi |k\in \mathbb{Z} \right\}$.
C. $D=\mathbb{R}\backslash \left\{ \dfrac{\pi }{12}+k\pi |k\in \mathbb{Z} \right\}$.
D. $D=\mathbb{R}\backslash \left\{ -\dfrac{\pi }{6}+k\dfrac{\pi }{2}|k\in \mathbb{Z} \right\}$.
Điều kiện: $\cos \left( 2x+\dfrac{\pi }{3} \right)\ne 0\Leftrightarrow 2x+\dfrac{\pi }{3}\ne \dfrac{\pi }{2}+k\pi \Leftrightarrow x\ne \dfrac{\pi }{12}+k\dfrac{\pi }{2}$.
Đáp án A.