BITSAT 2011 Paper

We have ae = 5 [Since focus is (±ae, 0)] and

a

e

=

36

5

[since directrix is x = ±

a

e

]
On solving we get a = 6 and e =

5

6

⇒ b2 = a2(1−e2) = 36 (1−

25

36

) = 11
Thus, the required equation of the ellipse is

x2

36

+

y2

11

= 1