Question

[Cao Văn Đạt]

Tìm tập xác định của hàm số

Answer 1

[Lê Thị Thục Hiền]

10) Đk \(\left\{{}\begin{matrix}sinx\ne0\\2cosx\ne0\end{matrix}\right.\)\(\Rightarrow sin2x\ne0\Leftrightarrow x\ne\dfrac{k\pi}{2}\)\((k\)\(\in\)\(Z\))

13) Đk \(sin\left(x+\dfrac{\pi}{3}\right)\ne0\) \(\Leftrightarrow x\ne\dfrac{-\pi}{3}+k\pi\)\((k\)\(\in\)\(Z\))

16) Đk \(\left\{{}\begin{matrix}cosx\ne0\\sin3x\ne0\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x\ne\dfrac{\pi}{2}+k\pi\\x\ne\dfrac{k\pi}{3}\end{matrix}\right.\)\((k\)\(\in\)\(Z\))

19) Đk \(\left\{{}\begin{matrix}cosx\ne0\\sinx\ne0\end{matrix}\right.\)\(\Rightarrow\dfrac{1}{2}sin2x\ne0\)\(\Leftrightarrow sin2x\ne0\)\(\Leftrightarrow x\ne\dfrac{k\pi}{2}\) \((k\)\(\in\)\(Z\)

Answer 2

[Lê Thị Thục Hiền]

Quên kl:

10) \(D=R\backslash\left\{\dfrac{k\pi}{2};k\in Z\right\}\)

13)\(D=R\backslash\left\{-\dfrac{\pi}{3}+k\pi;k\in Z\right\}\)

16)\(D=R\backslash\left\{\dfrac{\pi}{2}+k\pi,\dfrac{k\pi}{3};k\in Z\right\}\)

19)\(D=R\backslash\left\{\dfrac{k\pi}{2};k\in Z\right\}\)