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 Describe the languages denoted by the following regular expressions:

  1. $a(a\mid b)^{\ast}a.$
  2. $((\epsilon\mid a)b^{\ast})^{\ast}.$
  3. $(a\mid b)^{\ast}a(a\mid b)(a\mid b).$
  4. $a^{\ast}ba^{\ast}ba^{\ast}ba^{\ast}.$
  5. $(aa\mid bb)^{\ast}((ab\mid ba)(aa\mid bb)^{\ast}(ab\mid ba)(aa\mid bb)^{\ast})^{\ast}.$
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a). start and end with a.

b). (a+b)* or we can say universal set on symbols (a,b).

c). end with aaa or aab or aba or abb.

d). containing exactly 3 b's.

e). m solving (i will post (e) asap.)

correct me if wrong..
can we describe c) as third last symbola a


e). even no of a’s and b’s.

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