Aspire Faculty ID #18062 · Topic: JEE Main 2026 (24 January Evening Shift) · Just now
JEE Main 2026 (24 January Evening Shift)

Let the length of the latus rectum of an ellipse $ \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1 $, $ (a > b) $, be $30$. If its eccentricity is the maximum value of the function $ f(t) = -\frac{3}{4} + 2t - t^2 $, then $ (a^2 + b^2) $ is equal to

Solution

$ e^2 = \frac{1}{16} $

Then,

$ \frac{b^2}{a^2} = \frac{15}{16} $

$ b^2 = \frac{15}{16} a^2 $

$ \frac{2b^2}{a} = 30 $

$ \frac{2 \cdot 15}{16} a = 30 $

$ \frac{30}{16} a = 30 $

$ a = 16 $

$ b^2 = 240 $

$ a^2 = 256 $

$ a^2 + b^2 = 256 + 240 = 496 $

Previous 10 Questions — JEE Main 2026 (24 January Evening Shift)

Nearest first

Next 10 Questions — JEE Main 2026 (24 January Evening Shift)

Ascending by ID
1
Let the angles made with the positive $x$-axis by two straight lines drawn from the point $P(2, 3)$ and meeting the lin…
Topic: JEE Main 2026 (24 January Evening Shift)
2
Let $ \vec{a} = 2\hat{i} - \hat{j} - \hat{k}, \vec{b} = \hat{i} + 3\hat{j} - \hat{k} $ and $ \vec{c} = 2\hat{i} + \hat{…
Topic: JEE Main 2026 (24 January Evening Shift)
3
Let $ \alpha_1, \alpha_2, \alpha_3, \alpha_4 $ be an A.P. of four terms such that each term of the A.P. and its common …
Topic: JEE Main 2026 (24 January Evening Shift)
4
Let the image of parabola $ x^2 = 4y $, in the line $ x - y = 1 $ be $ (y + \alpha)^2 = b(x - c) $, $ a, b, c \in \math…
Topic: JEE Main 2026 (24 January Evening Shift)
5
$ \left( \frac{1}{3} + \frac{4}{7} \right) + \left( \frac{1}{3^2} + \frac{1}{3} \times \frac{4}{7} + \frac{4^2}{7^2} \r…
Topic: JEE Main 2026 (24 January Evening Shift)
6
Let $ P = [p_{ij}] $ and $ Q = [q_{ij}] $ be two square matrices of order $ 3 $ such that $ q_{ij} = 2^{(i + j - 1)} p_…
Topic: JEE Main 2026 (24 January Evening Shift)
7
The letters of the word "UDAYPUR" are written in all possible ways with or without meaning and these words are arranged…
Topic: JEE Main 2026 (24 January Evening Shift)
8
The largest value of $ n $, for which $ 40^n $ divides $ 60! $, is:
Topic: JEE Main 2026 (24 January Evening Shift)
9
The sum of all values of $ \alpha $, for which the shortest distance between the lines $ \frac{x+1}{\alpha} = \frac{y-…
Topic: JEE Main 2026 (24 January Evening Shift)
10
Let $ f(\alpha) $ denote the area of the region in the first quadrant bounded by $ x = 0, x = 1, y^2 = x $ and $ y = | …
Topic: JEE Main 2026 (24 January Evening Shift)
Ask Your Question or Put Your Review.

loading...