BCECE Engineering BCECE Engineering Solved Paper-2005

  • question_answer
    \[\frac{d}{dx}({{\sin }^{-1}}2x\sqrt{1-{{x}^{2}}})\]is equal to:

    A)  \[-\frac{2}{\sqrt{1-{{x}^{2}}}}\]                         

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

    C)        \[cos\,2x\]            

    D)         none of these

    Correct Answer: B

    Solution :

    \[\frac{d}{dx}({{\sin }^{-1}}2x\sqrt{1-{{x}^{2}}})\] Put,         \[x=\sin \theta \] \[\therefore \]      \[\frac{d}{dx}({{\sin }^{-1}}2\sin \theta \sqrt{1-{{\sin }^{2}}\theta })\] \[=\frac{d}{dx}(si{{n}^{-1}}2sin\theta cos\theta )\] \[=\frac{d}{dx}(si{{n}^{-1}}sin2\theta )=\frac{d}{d\theta }=\frac{d}{dx}(2\theta )\] \[=\frac{d}{dx}(2{{\sin }^{-1}}x)=\frac{2}{\sqrt{1-{{x}^{2}}}}\]


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