=1 General co ordinates are: (h+acosθ,k+bsinθ) Here the general co ordinates are (3cosθ,4sinθ) Hence h=k=0 &a=3,b=4 For horizontal ellipse: b2=a2(1−e2)( when b<a) Here, it is vertical ellipse, (∵b>a) ∴a=4,b=3 (i.e., we interchange normal a and b ) ⇒9=16(1−e2) ⇒
9
16
=1−e2 ⇒e2=1−
9
16
=
7
16
⇒e=
√7
4
The two focii lie on (O,I as) :Distance between them: =2ae =2×4×