a) \(y=\tan\left(2x-\dfrac{5\pi}{6}\right)\) xác định khi:
\(2x-\dfrac{5\pi}{6}\ne\dfrac{\pi}{2}+k\pi\left(k\in Z\right)\)
\(\Leftrightarrow2x\ne\dfrac{4\pi}{3}+k\pi\left(k\in Z\right)\)
\(\Leftrightarrow x\ne\dfrac{2\pi}{3}+\dfrac{k\pi}{2}\left(k\in Z\right)\)
Vậy \(D=R\backslash\left\{\dfrac{2\pi}{3}+\dfrac{k\pi}{2}\right\}\left(k\in Z\right)\)
b) \(y=\dfrac{x}{2\cos x-1}\) XĐ khi:
\(2\cos x-1\ne0\)
\(\Leftrightarrow\cos x\ne\dfrac{1}{2}\)
\(\Leftrightarrow x\ne\pm\dfrac{\pi}{3}+k2\pi\left(k\in Z\right)\)
Vậy ...
Đúng 1
Bình luận (0)
