L
loverain22


giải pt:
1) 2sin^3 x +4cos^3 x =3sinx
2) sin2x.sinx +cos5x.cos2x = (1+cos8x)/2
3)cos^4 x + sin^4 x = 1/2.trị tuyệt đối sin2x
4) cos^4 - sin^4 +cos 4x =0
1) 2sin^3 x +4cos^3 x =3sinx
2) sin2x.sinx +cos5x.cos2x = (1+cos8x)/2
3)cos^4 x + sin^4 x = 1/2.trị tuyệt đối sin2x
4) cos^4 - sin^4 +cos 4x =0