BCECE Engineering BCECE Engineering Solved Paper-2001

  • question_answer
    \[y=4\sin 3x\]is a solution of the differential equation:

    A) \[\frac{dy}{dx}+8y=0\]

    B)                         \[\frac{dy}{dx}-8y=0\]                 

    C)  \[\frac{{{d}^{2}}y}{d{{x}^{2}}}+9y=0\]

    D)         \[\frac{{{d}^{2}}y}{d{{x}^{2}}}-9y=0\]

    Correct Answer: C

    Solution :

    \[y=4\sin 3x\]                                                    ?(i) \[\Rightarrow \]               \[\frac{dy}{dx}=12\cos 3x\] \[\Rightarrow \]               \[\frac{{{d}^{2}}y}{d{{x}^{2}}}=-36\sin 3x\] \[\Rightarrow \]               \[\frac{{{d}^{2}}y}{d{{x}^{2}}}+9y=0\]                    [from (i)]


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