JEE Main & Advanced AIEEE Solved Paper-2002

  • question_answer
    \[\underset{x\to \infty }{\mathop{\lim }}\,{{\left( \frac{{{x}^{2}}+5x+3}{{{x}^{2}}+x+2} \right)}^{x}}\] is equal to   AIEEE  Solved  Paper-2002

    A) \[{{e}^{4}}\]

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

    C) \[{{e}^{3}}\]                         

    D)           e

    Correct Answer: A

    Solution :

    \[\underset{x\to \infty }{\mathop{\lim }}\,{{(1-\lambda x)}^{1/x}}={{e}^{\lambda }}\] Now, \[\underset{x\to \infty }{\mathop{\lim }}\,{{\left( \frac{{{x}^{2}}+5x+3}{{{x}^{2}}+x+2} \right)}^{x}}\]    \[=\underset{x\to \infty }{\mathop{\lim }}\,{{\left( 1+\frac{4x+1}{{{x}^{2}}+x+2} \right)}^{x}}\] \[=\underset{x\to \infty }{\mathop{\lim }}\,{{\left[ {{\left( 1+\frac{4x+1}{{{x}^{2}}+x+2} \right)}^{{1}/{\frac{(4x+1)}{{{x}^{2}}+x+2}}\;}} \right]}^{\frac{(4x+1)x}{{{x}^{2}}+x+2}}}\]    \[={{e}^{\underset{x\to \infty }{\mathop{\lim }}\,\frac{\left( 4+\frac{1}{x} \right)}{1+\frac{1}{x}+\frac{2}{{{x}^{2}}}}}}={{e}^{4}}\] 


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