Đáp án:
$\left[\begin{array}{l}x = \dfrac{\pi}{6} + k\dfrac{\pi}{3}\\x = \dfrac{\pi}{2} + k\pi\end{array}\right.\quad (k\in\Bbb Z)$
Giải thích các bước giải:
$\sin^2x =\cos^22x$
$\Leftrightarrow 1 - \cos2x = 1 + \cos4x$
$\Leftrightarrow \cos4x +\cos2x = 0$
$\Leftrightarrow \cos3x\cos x = 0$
$\Leftrightarrow \left[\begin{array}{l}\cos3x = 0\\\cos x = 0\end{array}\right.$
$\Leftrightarrow \left[\begin{array}{l}x = \dfrac{\pi}{6} + k\dfrac{\pi}{3}\\x = \dfrac{\pi}{2} + k\pi\end{array}\right.\quad (k\in\Bbb Z)$
