Q.

An ellipse has its center at (1, −2), one focus at (3, −2) and one vertex at (5, −2). Then the length of its latus rectum is :   [2026]

1 163  
2 63  
3 43  
4 6  

Ans.

(4)

CA1=a=4

CF1=ae=2

e=12

LR=2e(ae-ae)

=2×12(41/2-2)

= 6