JEE Main & Advanced Mathematics Functions Question Bank Limits

  • question_answer
                                                                                                                                                                        \[\underset{x\to 0}{\mathop{\lim }}\,\frac{x({{e}^{x}}-1)}{1-\cos x}=\]

    A)                 0

    B)                 \[\infty \]

    C)                 ?2

    D)                 2

    Correct Answer: D

    Solution :

                       \[\underset{x\to 0}{\mathop{\lim }}\,\,\,\,\frac{x\,({{e}^{x}}-1)}{1-\cos x}=\underset{x\to 0}{\mathop{\lim }}\,\,\frac{2x\,({{e}^{x}}-1)}{4.{{\sin }^{2}}\frac{x}{2}}\]                                                            \[=2\underset{x\to 0}{\mathop{\lim }}\,\,\left[ \frac{{{(x/2)}^{2}}}{{{\sin }^{2}}\frac{x}{2}} \right]\,\left( \frac{{{e}^{x}}-1}{x} \right)=2.\]


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