Question

Answer 1

\(cotx=-3\left(x\ne k\pi\right)\)

\(\Leftrightarrow x=arccotan\left(-3\right)+k\pi\)

\(sinx=\dfrac{1}{2}\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{\pi}{6}+k2\pi\\x=\dfrac{5\pi}{6}+k2\pi\end{matrix}\right.\)