How do we know that the updates improve things?
		• Updating each Gaussian definitely improves the probability of generating the data if we generate it from the same Gaussians after the parameter updates. – But we know that the posterior will change after updating the parameters. • A good way to show that this is OK is to show that there is a single function that is improved by both the E-step and the M-step. – The function we need is called Free Energy.