Question

2cos^3x-2cosx+sin^2x=0

Answer 1

$\2cos^3x-2cosx+1-cos^2x=0 \ \2cosx(cos^2x-1)-(cos^2x-1)=0 \ \(cos^2x-1)(2cosx-1)=0 \ \cos^2x-1=0 vee 2cosx-1=0 \ \cosx=-1 vee cosx=1 vee cosx=frac12 \ \x=npi vee x=fracpi3+2npi vee x=-fracpi3+2npi, nin Z$