The mean field approximation predicts that the average magnetization m is determined by where z is the number of nearest neighbors. (a) find the critical temperature te (b) show that the critical exponent for the magnetization is 1/2 .. (c) show that the internal energy is give by where n is the number of spins. (d) find the energy at b = 0 and t = 0, compare the result with the exact value. (e) find the energy for t > 「. is the result realistic?