2. The planar rotator of previous problem is in a state with the wave function ys (p) = Ccos2 p. (1) where C is the normalization constant. (a) Determine the probability of different values of the projection of the angular momentum, its average value and the dispersion. A quick way to expand the wave function (1) in eigenfunctions of l, determined in previous problem is to apply Euler's formula to Eq. (1). Also remember to normalize the wave function (1). (b) Determine the probability of different values of the energy, its average value and the dispersion. (c) Write down an expression for the time-dependent wave function of the planar rotator, show that it is periodic in time and find its period