Đáp án:
\(\left[ \begin{array}{l}x=-\dfrac{\pi}{2}+k2\pi\\x=\dfrac{\pi}{6}+\dfrac{k2\pi}{3}\end{array} \right.\)`(kinZZ)`
Giải thích các bước giải:
`sinx=cos2x`
`<=>cos2x=cos(x-pi/2)`
`<=>`\(\left[ \begin{array}{l}2x=x-\dfrac{\pi}{2}+k2\pi\\2x=-(x-\dfrac{\pi}{2})+k2\pi\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}x=-\dfrac{\pi}{2}+k2\pi\\3x=\dfrac{\pi}{2}+k2\pi\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}x=-\dfrac{\pi}{2}+k2\pi\\x=\dfrac{\pi}{6}+\dfrac{k2\pi}{3}\end{array} \right.\)`(kinZZ)`
