CET Karnataka Engineering CET - Karnataka Engineering Solved Paper-2011

  • question_answer
    The general solution of \[{{\left( \frac{dy}{dx} \right)}^{2}}=1-{{x}^{2}}-{{y}^{2}}+{{x}^{2}}{{y}^{2}}\]is

    A) \[2{{\sin }^{-1}}y=x\sqrt{1-{{x}^{2}}}+{{\sin }^{-1}}x+C\]

    B) \[{{\cos }^{-1}}y=x{{\cos }^{-1}}x+C\]

    C) \[{{\sin }^{-1}}y=\frac{1}{2}{{\sin }^{-1}}x+C\]

    D) \[2{{\sin }^{-1}}y=x\sqrt{1-{{y}^{2}}}+C\]

    Correct Answer: A

    Solution :

    Given, \[{{\left( \frac{dy}{dx} \right)}^{2}}=1-{{x}^{2}}-{{y}^{2}}+{{x}^{2}}{{y}^{2}}\] \[\Rightarrow \]               \[{{\left( \frac{dy}{dx} \right)}^{2}}=(1-{{x}^{2}})-{{y}^{2}}(1-{{x}^{2}})\] \[\Rightarrow \]               \[\frac{dy}{dx}=\sqrt{(1-{{x}^{2}})}\sqrt{(1-{{y}^{2}})}\] \[\int{\frac{dy}{(1-{{y}^{2}})}}=\int{\sqrt{(1-{{x}^{2}})}dx}\] (on integrating) \[\Rightarrow \] \[{{\sin }^{-1}}y=\frac{x}{2}\sqrt{1-{{x}^{2}}}+\frac{1}{2}{{\sin }^{-1}}x+\frac{C}{2}\] \[\Rightarrow \] \[2{{\sin }^{-1}}y=x\sqrt{1-{{x}^{2}}}+{{\sin }^{-1}}x+C\]


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