Gamma Function: Gamma(n) = integral(0 to infinity) t^(n-1) * e^(-t) dt = (n-1)! for positive integers.
Beta Function: B(m,n) = integral(0 to 1) x^(m-1)(1-x)^(n-1) dx = Gamma(m)*Gamma(m+n)
Connection to Wallis: integral sin^(2m-1) x * cos^(2n-1) x dx = B = Gamma(m)Gamma)
JEE Relevance: While the Gamma function itself is beyond JEE scope, knowing Gamma = sqrt(pi) explains why integral sqrt(sin x cos x) dx involves sqrt(pi).