CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2002

  • question_answer
    If\[\sin y+{{e}^{-x\cos y}}=e,\]then\[\frac{dy}{dx}\]at\[(1,\pi )\]is:

    A)  \[\sin y\]                            

    B)                         \[-x\cos y\]

    C)                         \[e\]    

    D)                          \[\sin y-x\cos y\]

    E)                         \[\sin y+x\cos y\]

    Correct Answer: C

    Solution :

                    \[\sin y+{{e}^{-x\cos y}}=e\] On differentiating w.r.t.\[x,\]we get \[\cos y\frac{dy}{dx}-{{e}^{-x\cos y}}\]                                 \[\times \left( -x\sin y\frac{dy}{dx}+\cos y \right)=0\] \[\Rightarrow \]\[(\cos y+x{{e}^{-x\cos y}}\sin y)\frac{dy}{dx}\]                                 \[={{e}^{-x\cos y}}\cos y\] At\[(1,\pi )\] \[\cos \pi {{\left( \frac{dy}{dx} \right)}_{(1,\pi )}}={{e}^{-\cos \pi }}.\cos \pi \] \[\Rightarrow \]               \[{{\left( \frac{dy}{dx} \right)}_{(1,\pi )}}=e\]                


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