3. Write a regular expression for each of the following languages. The alphabet = {a, b}. L1 = {x | x has a 3n+1 a's for some n>0 or x ends with baba L2 = {x | x does not begin with aa 4. Consider the following regular expression. The aphabet is {a,b,c,d}. (ab+c)*(b+dc*)*da* For each string listed below, determine whether the string is generated by the above regulalr expression. Circle those strings that are generated by the regular expression. bdccd abccabdccdaa abd cdccbbada cdda