Câu 2. Giải phương trình: (cos⁡x-1)(2sin⁡x-1)=0

`(cosx-1)(2sinx-1)=0`

`<=>[(cosx-1=0),(2sinx-1=0):}`

`<=>[(cosx=1),(2sinx=1):}`

`<=>` $\left[\begin{matrix} x=k2\pi\\ \sin(x)=\dfrac{1}{2}\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=k2\pi\\ \sin(x)=\sin\dfrac{\pi}{6}\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=k2\pi\\ x=\dfrac{\pi}{6}+k2\pi\\x=\pi-\dfrac{\pi}{6}+k2\pi\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x=k2\pi\\ x=\dfrac{\pi}{6}+k2\pi\\x=\dfrac{5\pi}{6}+k2\pi\end{matrix}\right.$ `(k \in ZZ)`