ĐKXĐ: \(x\ne\left\{\dfrac{\pi}{6}+k2\pi;\dfrac{5\pi}{6}+k2\pi\right\}\)
\(\dfrac{cosx-\sqrt{3}sinx}{2sinx-1}=0\)
\(\Rightarrow cosx=\sqrt{3}sinx\)
\(\Rightarrow tanx=\dfrac{1}{\sqrt{3}}\)
\(\Rightarrow x=\dfrac{\pi}{6}+k\pi\)
Kết hợp ĐKXĐ \(\Rightarrow x=-\dfrac{5\pi}{6}+k2\pi\)
ĐKXĐ: sinx<>1/2
\(\Leftrightarrow\left\{{}\begin{matrix}x< >\dfrac{pi}{6}+k2pi\\x< >\dfrac{5}{6}pi+k2pi\end{matrix}\right.\)
PT=>\(cosx-\sqrt{3}sinx=0\)
=>\(\sqrt{3}sinx-cosx=0\)
\(\Leftrightarrow sin\left(x-\dfrac{pi}{6}\right)=0\)
=>x-pi/6=kpi
=>x=kpi+pi/6
mà x<>pi/6+k2pi
nên x=7/6pi+k2pi
