JEE Mains · Maths · STD 11 - 10.2 parabola,ellipse,hyperbola
Let \(a>0, b>0\). Let \(e\) and \(\ell\) respectively be the eccentricity and length of the latus rectum of the hyperbola \(\frac{ x ^{2}}{ a ^{2}}-\frac{ y ^{2}}{ b ^{2}}=1\). Let \(e ^{\prime}\) and \(\ell^{\prime}\) respectively the eccentricity and length of the latus rectum of its conjugate hyperbola. If \(e ^{2}=\frac{11}{14} \ell\) and \(\left( e ^{\prime}\right)^{2}=\frac{11}{8} \ell^{\prime}\), then the value of \(77 a+44 b\) is equal to
- A \(100\)
- B \(110\)
- C \(120\)
- D \(130\)
Answer & Solution
Correct Answer
(D) \(130\)
Step-by-step Solution
Detailed explanation
\(e=\sqrt{1+\frac{b^{2}}{a^{2}}}, \ell=\frac{2 b^{2}}{a}\) Given \(e ^{2}=\frac{11}{14} \ell\) \(1+\frac{b^{2}}{a^{2}}=\frac{11}{14} \cdot \frac{2 b^{2}}{a}\) \(\frac{a^{2}+b^{2}}{a^{2}}=\frac{11}{7} \cdot \frac{b^{2}}{a}\)........\((1)\) Also…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- Let the positive numbers \(a _1, a _2, a _3, a _4\) and \(a _5\) be in a G.P. Let their mean and variance be \(\frac{31}{10}\) and \(\frac{ m }{ n }\) respectively, where \(m\) and \(n\) are co-prime. If the mean of their reciprocals is \(\frac{31}{40}\) and \(a_3+a_4+a_5=14\), then \(m + n\) is equal to \(.........\).JEE Mains 2023 Hard
- Let \(f(x)\) be a function satisfying \(f(x)+f(\pi-x)=\) \(\pi^2, \forall x \in R\). Then \(\int \limits_0^\pi f(x) \sin x d x\) is equal to \(...........\).JEE Mains 2023 Hard
- Let \(f: \mathbb{R} \rightarrow \mathbb{R}\) be a continuous function satisfying \(f(0)=1\) and \(f(2 \mathrm{x})-f(\mathrm{x})=\mathrm{x}\) for all \(\mathrm{x} \in \mathbb{R}\). If \(\lim _{n \rightarrow \infty}\left\{f(x)-f\left(\frac{x}{2^n}\right)\right\}=G(x)\), then \(\sum_{r=1}^{10} G\left(r^2\right)\) is equal toJEE Mains 2025 Hard
- Let \(S_n\) denote the sum of first \(n\) terms an arithmetic progression. If \(S_{20}=790\) and \(S_{10}=145\), then \(S_{15}-\) \(S_5\) is :JEE Mains 2024 Medium
- If \(\int \limits_{-0.15}^{0.15}\left|100 x ^2-1\right| dx =\frac{ k }{3000}\), then \(k\) is equal to \(..........\).JEE Mains 2023 Hard
- If the domain of the function \(f(x)=\log _e\left(4 x^2+11 x+6\right)+\sin ^{-1}\) \((4 x+3)+\cos ^{-1}\left(\frac{10 x+6}{3}\right) \text { is }(\alpha, \beta]\) Then \(36|\alpha+\beta|\) is equal to :JEE Mains 2023 Hard
More PYQs from JEE Mains
- If the Coefficient of \(x^{30}\) in the expansion of \(\left(1+\frac{1}{x}\right)^6\left(1+x^2\right)^7\left(1-x^3\right)^8 ; x \neq 0\) is \(\alpha\), then \(|\alpha|\) equalsJEE Mains 2024 Hard
- Let \(C\) be the locus of the mirror image of a point on the parabola \(y ^{2}=4 x\) with respect to the line \(y = x\). Then the equation of tangent to \(C\) at \(P (2,1)\) is :JEE Mains 2021 Medium
- Let \(S=\{z \in \mathbb{C}: z^2+4z+16=0\}\). Then \(\sum_{z \in S}|z+\sqrt{3}i|^2\) is equal to:JEE Mains 2026 Medium
- The sum of all rational terms in the expansion of \(\left(1+2^{1 / 3}+3^{1 / 2}\right)^6\) is equal toJEE Mains 2025 Easy
- The shortest distance between the lines \(\frac{x-3}{2}=\frac{y+15}{-7}=\frac{z-9}{5}\) and \(\frac{x+1}{2}=\frac{y-1}{1}=\frac{z-9}{-3}\) isJEE Mains 2024 Medium
- The sum \(1+\frac{1+3}{2!}+\frac{1+3+5}{3!}+\frac{1+3+5+7}{4!}+\ldots\) upto \(\infty\) terms, is equal toJEE Mains 2025 Easy