J & K CET Engineering J and K - CET Engineering Solved Paper-2003

  • question_answer
    \[\int{x|x|\,dx}\] is

    A)  \[\frac{{{x}^{2}}}{3}\]

    B)  \[-\frac{{{x}^{2}}}{3}\]

    C)  \[\frac{{{x}^{2}}|x|}{3}\]

    D)  None of these

    Correct Answer: C

    Solution :

    Let \[I=\int{\underset{II}{\mathop{x}}\,|\underset{I}{\mathop{x}}\,|dx}\] \[=|x|\frac{{{x}^{2}}}{2}-\int{\frac{|x|}{x}}.\frac{{{x}^{2}}}{2}\,\,dx\] \[\Rightarrow \] \[I=\frac{{{x}^{2}}|x|}{2}-\frac{I}{2}\] \[\frac{3I}{2}=\frac{{{x}^{2}}|x|}{2}\] \[\Rightarrow \] \[I=\frac{{{x}^{2}}|x|}{3}\]


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