Question

sin^4(x/2)-cos^4(x/2)=1/4
Помогите кто может)

Answer 1

$\cos^4 t-\sin^4 t=(\cos^2 t-\sin^2 t)(\cos^2 t+\sin^2 t)=\cos2t\\\\\cos x=1/4\\x=\pm\arccos(1/4)+2\pi k$