\( K=\bigcup_{k \in \mathbb{Z}}\left\{\frac{\pi}{3}+2 k \pi ; \frac{5 \pi}{3}+2 k \pi\right\} \)Unchecked
\( K=\bigcup_{k \in \mathbb{Z}}\left\{\frac{\pi}{2}+2 k \pi ; \frac{3 \pi}{2}+2 k \pi\right\} \)Unchecked
\( K=\bigcup_{k \in \mathbb{Z}}\left\{\frac{\pi}{6}+2 k \pi ; \frac{11 \pi}{6}+2 k \pi\right\} \)Unchecked
\( K=\bigcup_{k \in \mathbb{Z}}\left\{\frac{\pi}{4}+2 k \pi ; \frac{7 \pi}{4}+2 k \pi\right\} \)Unchecked