1.1.
\(sinx=\dfrac{1}{4}\Leftrightarrow\left[{}\begin{matrix}x=arcsin\dfrac{1}{4}+k2\pi\\x=\pi-arcsin\dfrac{1}{4}+k2\pi\end{matrix}\right.\)
1.2.
\(sinx=-\dfrac{\sqrt{3}}{2}\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{\pi}{6}+k2\pi\\x=\dfrac{7\pi}{6}+k2\pi\end{matrix}\right.\)
1.3.
\(sinx=-1\Leftrightarrow x=-\dfrac{\pi}{2}+k2\pi\)
1.4.
\(sin\left(x-\dfrac{\pi}{3}\right)=\dfrac{1}{2}\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{\pi}{3}=\dfrac{\pi}{6}+k2\pi\\x-\dfrac{\pi}{3}=\dfrac{5\pi}{6}+k2\pi\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{\pi}{2}+k2\pi\\x=\dfrac{7\pi}{6}+k2\pi\end{matrix}\right.\)