Đáp án:
\(x = \dfrac{\pi }{6}\)
Giải thích các bước giải:
\(\begin{array}{l}
\sin x = \dfrac{1}{2}\\
\to \left[ \begin{array}{l}
x = \dfrac{\pi }{6} + k2\pi \\
x = \dfrac{{5\pi }}{6} + k2\pi
\end{array} \right.\left( {k \in Z} \right)\\
Do:x \in \left[ { - \dfrac{\pi }{2};\dfrac{\pi }{2}} \right]\\
Thay:k = - 1\\
\to \left[ \begin{array}{l}
x = - \dfrac{{11\pi }}{6}\left( l \right)\\
x = - \dfrac{{7\pi }}{6}\left( l \right)
\end{array} \right.\\
Thay:k = 0\\
\to \left[ \begin{array}{l}
x = \dfrac{\pi }{6}\left( {TM} \right)\\
x = \dfrac{{5\pi }}{6}\left( l \right)
\end{array} \right.\\
Thay:k = 1\\
\to \left[ \begin{array}{l}
x = \dfrac{{13\pi }}{6}\left( l \right)\\
x = \dfrac{{17\pi }}{6}\left( l \right)
\end{array} \right.\\
KL:x = \dfrac{\pi }{6}
\end{array}\)
