1 votes 1 votes The regular expression for the language which have strings, starting and ending with different symbol, over $\Sigma = \{a,b\}$ is given by _______ (Mark all the appropriate choices) $a(a+b)^{\ast}b + b(a+b)^{\ast}b$ $a(a+b)^{\ast}b + a(a+b)^{\ast}a$ $b(a+b)^{\ast}a + a(a+b)^{\ast}a$ $a(a+b)^{\ast}b + b(a+b)^{\ast}a$ Theory of Computation go2025-mix-3 regular-expression multiple-selects + – gatecse asked Oct 15, 2020 • edited Oct 15, 2020 by Lakshman Bhaiya gatecse 43 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 1 votes 1 votes Given that, $\Sigma = \{a,b\}$ $L = \{ab,ba,aaab,bbba,\dots\}$ Now, regular expression $RE = a(a+b)^{\ast}b + b(a+b)^{\ast}a$ So, the correct answer is $(D).$ gatecse answered Oct 15, 2020 • selected Oct 9, 2021 by Arjun gatecse comment Share Follow See all 0 reply Please log in or register to add a comment.