Vũ Thị Hồng Nguyên
New member
Tập xác định của hàm số $y=\tan x+\cot x$ là:
A. $\mathbb{R}\backslash \left\{ k2\pi \,;\,k\in \mathbb{Z} \right\}$.
B. $\mathbb{R}\backslash \left\{ k\frac{\pi }{2}\,;\,k\in \mathbb{Z} \right\}$.
C. $\mathbb{R}\backslash \left\{ k\pi \,;\,k\in \mathbb{Z} \right\}$.
D. $\mathbb{R}\backslash \left\{ \frac{\pi }{2}+k\pi \,;\,k\in \mathbb{Z} \right\}$.
A. $\mathbb{R}\backslash \left\{ k2\pi \,;\,k\in \mathbb{Z} \right\}$.
B. $\mathbb{R}\backslash \left\{ k\frac{\pi }{2}\,;\,k\in \mathbb{Z} \right\}$.
C. $\mathbb{R}\backslash \left\{ k\pi \,;\,k\in \mathbb{Z} \right\}$.
D. $\mathbb{R}\backslash \left\{ \frac{\pi }{2}+k\pi \,;\,k\in \mathbb{Z} \right\}$.