CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2011

  • question_answer
    The value of the integral\[\int_{0}^{1}{x{{(1-x)}^{5}}dx}\]is equal to

    A)  \[\frac{1}{6}\]                                  

    B)  \[\frac{1}{7}\]     

    C)  \[\frac{6}{7}\]                  

    D)  \[\frac{5}{6}\]

    E)  \[\frac{1}{42}\]

    Correct Answer: E

    Solution :

    \[\int_{0}^{1}{x{{(1-x)}^{5}}dx}\] \[=\int_{0}^{1}{{{x}^{(2-1)}}}.{{(1-x)}^{(6-1)}}dx\] \[=B(2,6)\] \[\left[ \begin{align}   & \because B(m,n)=\int_{0}^{1}{{{x}^{m-1}}{{(1-x)}^{n-1}}dx} \\  & \because B(m,n)=\frac{\left| \!{\overline {\,  m \,}} \right. \,\left| \!{\overline {\,  n \,}} \right. }{\left| \!{\overline {\,  m \,}} \right. +\left| \!{\overline {\,  n \,}} \right. } \\ \end{align} \right]\]        \[=\frac{\left| \!{\overline {\,  2 \,}} \right. \,\,\left| \!{\overline {\,  6 \,}} \right. }{\left| \!{\overline {\,  (2+6) \,}} \right. }=\frac{\left| \!{\overline {\,  2 \,}} \right. \,\,\left| \!{\overline {\,  6 \,}} \right. }{\left| \!{\overline {\,  8 \,}} \right. }\] \[=\frac{1.5.4.3.2.1}{7.6.5.4.3.2.1}\] \[=\frac{1}{42}\]              


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