(i) Indicate the importance of renormalization group (RG) theory in a few sentences and then apply the RG theory to the one-dimensional spin-1/2 Ising model to obtain alternative RG equations. Clearly write down the most important result you will find. (10/100). (ii) Discuss in detail what should be considered when RG is applied to the two-dimensional spin-1/2 Ising system, and what is the most important result that can be achieved, unlike the one-dimensional one (5/100).