Let sigma = {a, b}. For each of the following languages, determine if it is a regular or not, and give a regular expression that represent each of the regular ones. The set of all strings on sigma that start with a or end with b. The set of all strings on sigma of even length Let L = {ab, aa, baa}. Which of the strings bbbbaa, aaabbaa, abaabaaabaa, baaaaabaaaab, and baaaaabaa are in L*? For each string in L* show how it was formed. Let sigma ={a, b). Prove that {a, b}* = a*. (b. a*)* Let sigma = {a, b}. Find regular expressions for the following languages over sigma. L_s = {a^mb^n|m greaterthanorequalto 4 alpha n lessthanorequalto 3, m, n element N}. L_t = L_s, the language complement to the one specified in "a