Question
Question: If the eccentricity of the ellipse \(\frac{x^{2}}{a^{2} + 2} + \frac{y^{2}}{a^{2} + 5}\)= 1 be\(\fra...
If the eccentricity of the ellipse a2+2x2+a2+5y2= 1 be31, then length of latus rectum of ellipse is
A
4
B
618
C
610
D
8
Answer
4
Explanation
Solution
Clearly a2 + 5 > a2 + 2
So (a2 + 2) = (a2 + 5) (1−31)
3a2 + 6 = 2a2 + 10 Ž a2 = 4
\ equation of ellipse is 6x2+9y2=1
\ length of latus rectum = 32×6=4