A) 8
B) 12
C) 18
D) 24
Correct Answer: C
Solution :
\[a=6,\ b=2\sqrt{5}\] \[{{b}^{2}}={{a}^{2}}(1-{{e}^{2}})\] Þ \[\frac{20}{36}=(1-{{e}^{2}})\] Þ \[e=\sqrt{\frac{16}{36}}=\frac{2}{3}\] But directrices are \[x=\pm \frac{a}{e}\] Hence distance between them is 2.\[\frac{6}{2/3}=18\].You need to login to perform this action.
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