JEE Main 2024 · MathsMultiple choiceSingle correctEasyMulti-step

JEE Main 9 April 2024, Shift 1, Maths Q12

Question 12 of 90 in this shift, Maths question 12 of 30, Section A.

Let

f(x)=x^2+9

g(x)=\frac{x}{x-9}

and

a=f\circ g(10)

b=g\circ f(3)

. If

e

and

l

denote the eccentricity and the length of the latus rectum of the ellipse

\frac{x^2}{a}+\frac{y^2}{b}=1

, then

8e^2+l^2

is equal to.

(1) $16$
(2) $12$
(3) $8$ Official answer
(4) $6$

Official answer

Option 3

NTA final key.

Chapter: Conic Sections
Topic: Ellipse Eccentricity
Idea tested: Length of Latus Rectum

Same idea in other shifts

Asked 12× in all

4 Apr 2026, Shift 1 · Q22Consider the parabola $P: y^2=4kx$ and the ellipse $E: \frac{x^2}{a^2}+\frac{y^2}{b^2}=1$ . Let the line segment joining the points of…MediumNumerical value
7 Apr 2025, Shift 2 · Q12Let the length of a latus rectum of an ellipse $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$ be 10. If its eccentricity is the minimum value of the…MediumSingle correct
5 Apr 2024, Shift 1 · Q15Let the line $2x+3y-k=0$ , $k>0$ , intersect the $x$ -axis and $y$ -axis at the points A and B, respectively. If the equation of the circle…MediumSingle correct
1 Feb 2024, Shift 1 · Q13Let $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$ , $a>b$ be an ellipse, whose eccentricity is $\frac{1}{\sqrt{2}}$ and the length of the latusrectum…MediumSingle correct
31 Jan 2024, Shift 1 · Q28Let the foci and length of the latus rectum of an ellipse $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1,\ a>b$ be $(\pm5,0)$ and $\sqrt{50}$ ,…MediumNumerical value
31 Jan 2024, Shift 2 · Q14Let $P$ be a parabola with vertex $(2,3)$ and directrix $2x+y=6$ . Let an ellipse $E:\frac{x^2}{a^2}+\frac{y^2}{b^2}=1,\ a>b$ , of…HardSingle correct
6 Apr 2023, Shift 2 · Q27Let the eccentricity of an ellipse $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$ is reciprocal to that of the hyperbola $2x^2-2y^2=1$ . If the…HardNumerical value
27 Jul 2022, Shift 1 · Q24An ellipse $E : \dfrac{x^2}{a^2} + \dfrac{y^2}{b^2} = 1$ passes through the vertices of the hyperbola…HardNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.