I need help

b. 25 points) Regular languages: Textbook problem 1.47 on p. 90. Hint: Consider closure properties =(14) Prove Y is not regular. For each string in the table below place a check mark in the appropriate box to indicate whether the string is in Y or is not in Y. string 1#1 1#11 11#1 1#11#1 1#11#111 111#1#11 11##1 111