MathematicsMedium178×since 2002Q5333If A=∑n=1∞1(3+(−1)n)nA = \sum\limits_{n = 1}^\infty {{1 \over {{{\left( {3 + {{( - 1)}^n}} \right)}^n}}}}A=n=1∑∞(3+(−1)n)n1 and B=∑n=1∞(−1)n(3+(−1)n)nB = \sum\limits_{n = 1}^\infty {{{{{( - 1)}^n}} \over {{{\left( {3 + {{( - 1)}^n}} \right)}^n}}}}B=n=1∑∞(3+(−1)n)n(−1)n, then AB{A \over B}BA is equal to :A119{{11} \over 9}911B1C−-−119{{11} \over 9}911D−-−113{{11} \over 3}311Check answerSkip