CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2000

  • question_answer
    The term independent of\[x\]in the expansion of \[{{(1+x)}^{n}}{{\left[ 1+\left( \frac{1}{x} \right) \right]}^{n}}\]is:

    A)  \[C_{0}^{2}+2C_{1}^{2}+3C_{2}^{2}+...+(n+1)C_{n}^{2}\]

    B)         \[{{C}_{1}}+{{C}_{2}}+{{C}_{3}}+....+{{C}_{n}}\]

    C)         \[C_{0}^{2}+C_{1}^{2}+C_{2}^{2}+....+C_{n}^{2}\]

    D)         \[{{C}_{1}}+2{{C}_{2}}+3{{C}_{3}}+....+n{{C}_{n}}\]

    E)         none of the above

    Correct Answer: C

    Solution :

    \[{{(1+x)}^{n}}{{\left[ 1+\frac{1}{x} \right]}^{n}}\] \[=({{C}_{0}}+{{C}_{1}}x+...+{{C}_{n}}{{x}^{n}})\]                                 \[\times \left( {{C}_{0}}+\frac{{{C}_{1}}}{x}+\frac{{{C}_{2}}}{{{x}^{2}}}+.....+\frac{{{C}_{n}}}{{{x}^{n}}} \right)\] So term independent of\[x\]is \[C_{0}^{2}+C_{1}^{2}+C_{2}^{2}+....+C_{n}^{2}\]


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