Prove that the following are not regular languages.
a) The set of strings of 0's and 1's whose length is a perfect square.
b)The set of strings of 0's and 1's that are of the form ww^R, that is, some string followed by its reverse.
c) The set of strings of the form w1^n, where w is a string of 0's and 1's of length n.