Question

mọi người giải một cách chi tiết nhất cho e dc k ạ

Answer 1

d: ĐKXĐ: \(3x< >k\Omega\)

=>\(x< >\dfrac{k\Omega}{3}\)

\(cot^23x-cot3x-2=0\)

=>\(cot^23x-2cot3x+cot3x-2=0\)

=>\(\left(cot3x-2\right)\left(cot3x+1\right)=0\)

=>\(\left[{}\begin{matrix}cot3x-2=0\\cot3x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}cot3x=2\\cot3x=-1\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}3x=arccot\left(2\right)+k\Omega\\3x=-\dfrac{\Omega}{4}+k\Omega\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=\dfrac{1}{3}\cdot arccot\left(2\right)+\dfrac{k\Omega}{3}\\x=-\dfrac{\Omega}{12}+\dfrac{k\Omega}{3}\end{matrix}\right.\)