Question

3cosx-cos^2 x=0

Answer 1

$3cosx-cos^2x=0 \ cosx(3-cosx)=0 \ \ cosx=0 \ x= frac{ pi }{2} + pi k \ \ 3-cosx=0 \ cosx neq 3$


Ответ: $x= frac{ pi }{2} + pi k$