Đáp án: \(\left[ \begin{array}{l}x=\dfrac{π}{4} + k \dfrac{π}{2}\\x=\dfrac{kπ}{3}\end{array} \right.\)
Giải thích các bước giải:
ĐK: `sin2x \ne 0 <=> 2x \ne kπ <=> x \ne k π/2`
`cot 2x . sin 3x =0`
`<=>` \(\left[ \begin{array}{l}cot2x=0\\sin3x=0\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}2x=\dfrac{π}{2} + kπ\\3x=kπ\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x=\dfrac{π}{4} + k \dfrac{π}{2}\\x=\dfrac{kπ}{3}\end{array} \right.\)
