BCECE Engineering BCECE Engineering Solved Paper-2012

  • question_answer
    \[\underset{x\to \infty }{\mathop{\lim }}\,{{\left( \frac{x+a}{a+b} \right)}^{x+b}}\]is

    A)  1                                            

    B)         \[{{e}^{b-a}}\]                 

    C)         \[{{e}^{a-b}}\]                                 

    D)         \[{{e}^{b}}\]

    Correct Answer: C

    Solution :

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


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