1)in a triangle ABC angleB and angle c is 2\theta BD bisects angle B
0< \theta<45 satisfies
2\cos\theta \sin\theta(1+2\cos\theta) = \sin4\theta + \sin\theta
the angleA of triangle ABC is

2) if 0<\alpha<\frac{\pi}{2} and 0<\beta<\frac{\pi}{2} and \cos\alpha\cos\beta\cos\(\alpha +\beta) = \frac{-1}{8}

then \alpha\beta = ??