JEE Main & Advanced Mathematics Conic Sections Question Bank Hyperbola

  • question_answer
    The equation of the hyperbola whose conjugate axis is 5 and the distance between the foci is 13, is

    A)            \[25{{x}^{2}}-144{{y}^{2}}=900\]     

    B)            \[144{{x}^{2}}-25{{y}^{2}}=900\]

    C)            \[144{{x}^{2}}+25{{y}^{2}}=900\]    

    D)            \[25{{x}^{2}}+144{{y}^{2}}=900\]

    Correct Answer: A

    Solution :

                       Conjugate axis is 5 and distance between foci = 13 Þ \[2b=5\]and\[2ae=13\].            Now, also we know for hyperbola                           \[{{b}^{2}}={{a}^{2}}({{e}^{2}}-1)\] Þ \[\frac{25}{4}=\frac{{{(13)}^{2}}}{4{{e}^{2}}}({{e}^{2}}-1)\]            Þ \[\frac{25}{4}=\frac{169}{4}-\frac{169}{4{{e}^{2}}}\] or \[{{e}^{2}}=\frac{169}{144}\] Þ \[e=\frac{13}{12}\]                    or \[a=6,\,b=\frac{5}{2}\] or hyperbola is \[\frac{{{x}^{2}}}{36}-\frac{{{y}^{2}}}{25/4}=1\]                    Þ \[25{{x}^{2}}-144{{y}^{2}}=900\].


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