Find the eccentricity, coordinates of foci, length of the latus - rectum of the following ellipse:
25x2 + 16y2 = 1600
Given the equation of the ellipse is 25x2 + 16y2 = 1600.
We need to find the eccentricity, coordinates of foci and length of latus rectum.

Given equation can be rewritten as ![]()
⇒
.
We know for the ellipse
(b2>a2)
⇒ ![]()
⇒ Coordinates of foci (0,±be)
⇒ Length of latus rectum = ![]()
Here a2 = 64 and b2 = 100, b2>a2
⇒ ![]()
⇒ ![]()
⇒ ![]()
⇒ ![]()
⇒ ![]()
⇒ foci = (0,±6)
⇒ Length of latus rectum (L) = ![]()
⇒ ![]()
∴ The eccentricity is
, foci are (0,±6) and length of the latus rectum is
.