Let the foci of a hyperbola be (1,14) and (1,-12). If it passes through the point (1,6), then the length of its latus-rectum is :
- 256
- 1445
- 2885
- 245
Answer
(3) 2885
Solution
Both foci lie on x=1 transverse axis is vertical, centre =(1,1), 2ae=26.
[figure]
(1,6) lies on the axis, so it is a vertex: a=6-1=5, ae=13
b2=a2e2-a2=169-25=144
Latus rectum = 2b2a= 2885
Answer: (3)