Question

помогите пожалуйста!!!!!

Answer 1

$Sin^{2} \frac{x}{4}-Cos^{2} \frac{x}{4}=1\\\\Cos^{2}\frac{x}{4}-Sin^{2}\frac{x}{4}=-1\\\\Cos\frac{x}{2} =-1\\\\\frac{x}{2}=\pi +2\pi n,nez\\\\x=2\pi+4\pi n,nez$