If the area of the ellipse is x^225+ y^2 ^2=1 is 20 square units, then is

Correct answer: A. (a) : We have, x^225+ y^2 ^2=1 Area of ellipse x^2a^2+ y^2b^2=1 is πab. ∴ 5 | |=20 (Given) ⇒ | |=4 ⇒ = 4

JEE Previous Year Question

$If the area of the ellipse is \frac{x ^{2}}{25} + \frac{y ^{2}}{λ ^{2}} = 1 is 20 π square units, then λ is$

Topic: JEE PYQ

Answer: A. Full step-by-step solution below.

Correct answer: A

(a) : We have, \frac{x ^{2}}{25} + \frac{y ^{2}}{λ ^{2}} = 1 Area of ellipse \frac{x ^{2}}{a ^{2}} + \frac{y ^{2}}{b ^{2}} = 1 is πab . ∴ π \cdot 5 \cdot | λ | = 20 π (Given) \Rightarrow | λ | = 4 \Rightarrow λ = \pm 4