Question

Answer 1

\(< =>\left(3sin3x-4sin^33x\right)-\sqrt{3}cos9x=1\)
\(< =>sin9x-\sqrt{3}cos9x=1\)
\(< =>sin\left(9x-\dfrac{\pi}{3}\right)=sin\dfrac{\pi\pi}{6}< =>\left[{}\begin{matrix}x=\dfrac{\pi}{18}+k\dfrac{2\pi}{9}\\x=\dfrac{7\pi}{54}+k\dfrac{2\pi}{9}\end{matrix}\right.\)