JEE Main & Advanced Sample Paper JEE Main - Mock Test - 45

  • question_answer
    The distance of a point P, on the ellipse \[{{x}^{2}}+3{{y}^{2}}=6\] lying in the first quadrant, from the centre of the ellipse is 2 units. The eccentric angle of the point P is-

    A) \[\frac{\pi }{3}\]            

    B)        \[\frac{\pi }{4}\]

    C) \[\frac{\pi }{6}\]            

    D)        None of these

    Correct Answer: B

    Solution :

    [b] Let \[P\left( \sqrt{6}cos\theta ,\text{ }\sqrt{2}sin\theta  \right)\] be a point on the ellipse \[\frac{{{x}^{2}}}{6}+\frac{{{y}^{2}}}{2}=1\] in the first-quadrant \[\left( 0<\theta <\frac{\pi }{2} \right)\] \[C{{P}^{2}}=6co{{s}^{2}}\theta +2si{{n}^{2}}\theta =4\] \[\Rightarrow 2+4co{{s}^{2}}\theta =4\] \[\Rightarrow co{{s}^{2}}\theta =\frac{1}{2}\] \[\Rightarrow cos\theta =\frac{1}{\sqrt{2}}\Rightarrow \theta =\frac{\pi }{4}\]


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