JEE Main & Advanced Mathematics Differentiation Question Bank Mock Test - Limits and Derivatives

  • question_answer
    \[\underset{n\to \infty }{\mathop{\lim }}\,{{\left( \frac{{{n}^{2}}-n+1}{{{n}^{2}}-n-1} \right)}^{n(n-1)}}\]is equal to

    A) \[e\]                 

    B) \[{{e}^{2}}\]

    C) \[{{e}^{-1}}\]            

    D) 1

    Correct Answer: B

    Solution :

    [b] \[\underset{n\to \infty }{\mathop{\lim }}\,{{\left( \frac{{{n}^{2}}-n+1}{{{n}^{2}}-n-1} \right)}^{n(n-1)}}=\underset{n\to \infty }{\mathop{\lim }}\,{{\left( \frac{n(n-1)+1}{n(n-1)-1} \right)}^{n(n-1)}}\] \[=\underset{n\to \infty }{\mathop{\lim }}\,\frac{{{\left( 1+\frac{1}{n(n-1)} \right)}^{n(n-1)}}}{{{\left( 1-\frac{1}{n(n-1)} \right)}^{n(n-1)}}}=\frac{e}{{{e}^{-1}}}={{e}^{2}}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner