Let L be the language over {a, b} that contains the same number of occurrences of a
and b. Which of the following languages is regular?
(a) L ∩ a∗b∗
(b) (L ∩ a∗b∗) ∪ a∗b∗
(c) L ∪ a∗b∗
(d) (L ∩ a∗b∗) ∪ b∗a
My personal doubts :( Sorry, this somewhat will reveeal the answer but I am a little confused )
Could someone please explain ( c ) and ( d ) ?
I have posted their official answer below as well.
One more thing, RL are closed under union, intersection.
L 1= a*b* is regular and and L is regular.
However L1 union/intersection L is not regular … Could someone please explain this question in some detail ?