Hàm số \(y=\sin x\) xác định trên
\(\mathbb{R}\backslash\left\{k\pi|k\in\mathbb{Z}\right\}\).\(\mathbb{R}\backslash\left\{\dfrac{k\pi}{2}|k\in\mathbb{Z}\right\}\).\(\mathbb{R}\backslash\left\{\dfrac{\pi}{2}+k\pi|k\in\mathbb{Z}\right\}\).\(\mathbb{R}\).