1.

`lim_(n -> oo) (((n+1)(n+2)(n+3).......3n) / n^(2n))^(1/n)`is equal toA. `27/(e^(2)0`B. `9/(e^(2))`C. `3log3-2`D. `18/e^(4)`

Answer» Correct Answer - A
`L=int_(nto oo) (((n+1)(n+2)……….(n+2n))/(n^(2n)))^(1//n)`
`:. log_(e)L=1/n(lim_(nto oo) sum_(r=1)^(2n)log(1+4/n))`
`:.log_(e)L=int_(0)^(2)log(1+x)dx`
`:.log_(e)L(xlog(1+x))_(0)^(2)-int_(0)^(2)x/(1+x)dx`
`:.log_(e)L=2log_(e)3-int_(0)^(2)(1-1/(1+x))dx`
`:. log_(e)L=2log3-(x-log(1+x))_(0)^(2)`
`=log_(e)L=2log3-(2-log3)`
`:.log_(e)L=3log3-2="log"27/(e^(2))`
`:.L=27/(e^(2))`


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