JAMIA MILLIA ISLAMIA Jamia Millia Islamia Solved Paper-2006

  • question_answer
        Equation of the ellipse whose foci are (2, 2) and (4, 2) and the major axis is of length 10, is

    A)  \[\frac{{{(x+3)}^{2}}}{24}+\frac{{{(y+2)}^{2}}}{25}=1\]

    B)  \[\frac{{{(x-3)}^{2}}}{24}+\frac{{{(y-2)}^{2}}}{25}=1\]

    C)  \[\frac{{{(x+3)}^{2}}}{24}+\frac{{{(y+2)}^{2}}}{24}=1\]

    D)  \[\frac{{{(x-3)}^{2}}}{25}+\frac{{{(y-2)}^{2}}}{24}=1\]

    Correct Answer: D

    Solution :

                    Since given that foci of an ellipse are (2, 2) and (4,2). \[\therefore \]Focal distance = 2 and centre of ellipse is (3, 2)            ...(i) \[\Rightarrow \]               \[2ae=2\]            and       \[2a=10\]                                              (given) \[\Rightarrow \]               \[a=5\]                                  ...(ii) \[\Rightarrow \]            \[e=\frac{1}{5}\]                                 ...(iii) Also, we know \[{{b}^{2}}={{a}^{2}}(1-{{e}^{2}})\] \[\therefore \]  \[{{b}^{2}}=25\left( 1-\frac{1}{25} \right)=\frac{24}{25}\times 25=24\] \[\Rightarrow \]                \[{{b}^{2}}=24\]                                           ...(iv) From Eqs. (i), (ii), (hi) and (iv) Equation of ellipse is                 \[\frac{{{(x-3)}^{2}}}{25}+\frac{{{(y-2)}^{2}}}{24}=1\]


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