Question

Решить уравнение: (1+cosx)(3-2cosx)=0

Answer 1

$\[\left[ \begin{array}{l} 1 + \cos x = 0\\ 3 - 2\cos x = 0 \end{array} \right.\left[ \begin{array}{l} \cos x = - 1\\ \cos x = \frac{3}{2} \end{array} \right.\left[ \begin{array}{l} x = \pi + 2\pi n,n \in z\\ \emptyset \end{array} \right.\]$