Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas 2020
Exam
NTA Abhyas
Year
2020
Subject
Mathematics
Chapter
Ellipse

NTA Abhyas 2020 · Mathematics · Ellipse

Let S and S^ ′ are the focii of the ellipse x = 3 + 5cos θ, y = - 2...

Let SS and S′S^{′} are the focii of the ellipse x=3+5cosθ,y=−2+4sinθ.x = 3 + 5cos \theta, y = - 2 + 4sin \theta. If BB is one of the ends of one of the latus rectum, then the area (in sq. units) of the triangle BSS′BSS^{′} is equal to

Options

  1. A245\dfrac{24}{5}
  2. B485\dfrac{48}{5}
  3. C125\dfrac{12}{5}
  4. D645\dfrac{64}{5}

Correct answer

B. 485\dfrac{48}{5}

Step-by-step solution

Assume the base of \DeltaSS′B\text{\Delta}SS^{′} B is SS′SS^{′}, then
base =SS′=2ae= SS^{′} = 2ae
height =12(2b2a)=lengthoflatusrectum2= \dfrac{1}{2}\left(\dfrac{2b^{2}}{a}\right) = \dfrac{lengthoflatusrectum}{2}
⇒area of \DeltaBSS′=12(2ae)(b2a)=b2e⇒ \text{area of \Delta}BSS^{′} = \dfrac{1}{2} \left(2ae\right)\left(\dfrac{b^{2}}{a}\right)= b^{2}e
Now, equation of the ellipse is (x−3)225+(y+2)216=1\dfrac{{\left(x - 3\right)}^{2}}{25} + \dfrac{{\left(y + 2\right)}^{2}}{16} = 1
⇒a2=25,b2=16,e2=925⇒ a^{2} = 25, b^{2} = 16, e^{2} = \dfrac{9}{25}
⇒b2e=16×35=485⇒ b^{2}e = 16 \times \dfrac{3}{5} = \dfrac{48}{5}

Hence, area of \DeltaBSS′=485\text{\Delta}BSS^{′}= \dfrac{48}{5}& sq. units

Practice Ellipse on Quantrex Academy →

More from Ellipse

Consider the ellipse E given by (x^2)/(18) + (y^2)/(12) = 1 . Let H be the hyperbola… JEE Advanced 2026Passage: Consider the ellipses given by x^2 + 4y^2 = 1 and 4x^2 + y^2 = 1 . Question: Let… JEE Advanced 2026Let (x^2)/(f(a^2+7a+3)) + (y^2)/(f(3a+15)) = 1 represent an ellipse with major axis along… JEE Main 2026The eccentricity of an ellipse E with centre at the origin O is 3 2 and its directrices… JEE Main 2026Let x = 9 be a directrix of an ellipse E , whose centre is at the origin and eccentricity… JEE Main 2026Let a focus of the ellipse E: (x^2)/(a^2) + (y^2)/(b^2) = 1 be S(4, 0) and its… JEE Main 2026Let A be the point (3, 0) and circles with variable diameter AB touch the circle x^2 +… JEE Main 2026Let an ellipse (x^2)/(a^2) + (y^2)/(b^2) = 1 , a < b , pass through the point (4, 3) and… JEE Main 2026An ellipse has its center at (1,-2) , one focus at (3,-2) and one vertex at (5,-2) . Then… JEE Main 2026Let the ellipse E: x^ 2 144 + y^ 2 169 =1 and the hyperbola H: x^ 2 16 - y^ 2 λ^ 2 =-1… JEE Main 2026Let the length of the latus rectum of an ellipse x^ 2 a^ 2 + y^ 2 b^ 2 =1,(a>b) , be 30.… JEE Main 2026Let (h, k) lie on the circle C: x^ 2 +y^ 2 =4 and the point (2 h+1,3 k+2) lie on an… JEE Main 2026Let each of the two ellipses E_ 1 : x^ 2 a^ 2 + y^ 2 b^ 2 =1,(a>b) and E_ 2 : x^ 2 ~A^ 2… JEE Main 2026Let the line y-x=1 intersect the ellipse x^ 2 2 + y^ 2 1 =1 at the points A and B. Then… JEE Main 2026Let S and S^ be the foci of the ellipse x^ 2 25 + y^ 2 9 =1 and P(α, β) be a point on the… JEE Main 2026If the line α x+4 y= 7 , where α ∈ R , touches the ellipse 3 x^ 2 +4 y^ 2 =1 at the point… JEE Main 2026 Full Ellipse list Ellipse JEE Maths PYQsJEE Mathematics PYQs All NTA Abhyas JEE Main PYQs