JEE Main & Advanced Sample Paper JEE Main Sample Paper-1

  • question_answer
    The distance between the point (1, 1) and the tangent to the curve \[y={{e}^{2x}}+{{x}^{2}}\] drawn from the point x = 0 is

    A)  \[\frac{1}{\sqrt{5}}\]                                    

    B)  \[-\frac{1}{\sqrt{5}}\]

    C)  \[\frac{2}{\sqrt{5}}\]                                    

    D)  \[-\frac{2}{\sqrt{5}}\]

    Correct Answer: C

    Solution :

    The equation of given curve is \[y={{e}^{2x}}={{x}^{2}}\]                                            ...(i) On putting x = 0 in Eq. (i), we get y = 1 \[\therefore \]The given point is P (0,1). On differentiating Eq. (i) w.r.t. x, we get \[\frac{dy}{dx}=2{{e}^{2x}}+2x\] \[\therefore \]\[{{\left( \frac{dy}{dx} \right)}_{(0,1)}}=2\] Equation of tangent at P(0,1) to Eq. (i) is \[y-1=2(x-0)\]\[\Rightarrow \]\[2x-y+1=0\]         ?(ii) \[\therefore \]Required distance =length of perpendicular from (1,1) to the line \[2x-y+1=0\]                      \[=\frac{2-1+1}{\sqrt{4+1}}=\frac{2}{\sqrt{5}}\]


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