2sin^24x –4=3*sin4x * cos4x – 4cos^24x
2sin^24x –4*(sin^24x+cos^24x)=3*sin4x * cos4x – 4cos^24x
-2sin^24x =3*sin4x * cos4x
2tg^24x+3tgx=0
tg4x*(2tg4x+3)=0
tg4x=0 или tg4x=-1,5
4x=arctg0+πk, k ∈ Z или 4x=arctg1,5+πn, n ∈ Z
x=(π/4)k, k ∈ Z или x=(1/4)arctg1,5+(π/4)*n, n ∈ Z
О т в е т. (π/4)k, (1/4)arctg1,5+(π/4)*n, k, n ∈ Z