1) alpha>0: in this case -alpha is negative, thus we want (2cos^2(t)-sin^2(t)) to be maximal (since then we substract the biggest number of the energy), thus theta = 0° or 180°
2) alpha<0: now -alpha is positive, thus we want (2cos^2(t)-sin^2(t)) to be minimal (since then we add the smallest number to the energy), thus theta = 90° or 270°
3) alpha = 0: in this case there is no corrections and thus all orientations lead to the same energy, which is equal to the monopole energy.