CET Karnataka Engineering CET - Karnataka Engineering Solved Paper-2001

  • question_answer
    If \[y=(1+{{x}^{2}}){{\tan }^{-1}}x-x,\]then \[\frac{dy}{dx}=\]

    A)  \[{{\tan }^{-1}}x\]                          

    B) \[2x{{\tan }^{-1}}x\]

    C)  \[2x{{\tan }^{-1}}x\]                     

    D)  \[\frac{2x}{{{\tan }^{-1}}x}\]

    Correct Answer: B

    Solution :

    \[y=(1+{{x}^{2}}){{\tan }^{-1}}x-x\] \[\Rightarrow \]\[y={{\tan }^{-1}}x+{{x}^{2}}{{\tan }^{-1}}x-x\] \[\Rightarrow \]\[\frac{dy}{dx}=\frac{1}{1+{{x}^{2}}}+{{x}^{2}}.\frac{1}{1+{{x}^{2}}}+{{\tan }^{-1}}x.2x-1\] \[\Rightarrow \]\[\frac{dy}{dx}=1+2x{{\tan }^{-1}}x-1\Rightarrow \frac{dy}{dx}=2x{{\tan }^{-1}}x\]


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