Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Advanced2015MathematicsEllipseActual

Let E 1 and E 2 be two ellipse whose centers are at the origin. The major axes of E 1 a n d E 2 lie along the x - axis and the y - axis, respectively. Let S be the circle x 2 + y - 1 2 = 2 . The straight line x + y = 3 touches the curves S , E 1 and E 2 at P , Q and R , respectively. Suppose that P Q = P R = 2 2 3 . If e 1 and e 2 are the eccentricities of E 1 and E 2 , respectively, then the correct expression(s) is

Options

  1. Ae 1 2 + e 2 2 = 43 40
  2. Be 1 e 2 = 7 2 10
  3. Ce 1 2 - e 2 2 = 5 8
  4. De 1 e 2 = 3 4

Correct answer

A. e 1 2 + e 2 2 = 43 40

Step-by-step solution

Let Q be ( x 1 ,   y 1 ) So equation tangent at Q will be x x 1 + y y 1 - y + y 1 - 1 = 0 Comparing with x + y = 3 x 1 y 1   ≡ ( 1,2 ) So R and Q will be 1   ± 2 2 3 cos ⁡ 3 π 4 ,   2 ± 2 2 3 sin ⁡ 3 π 4 ⇒     Q   5 3   , 4 3   a n d   1 3   , 8 3 Let Q lies on x 2   a 2 +   y 2 b 2 = 1 So tangent at P is 5 x 3 a 2 + 4 y 3 b 2 = 1 Comparing with x + y = 3 a 2 = 5 ,   b 2 = 4   ⇒ e 1 = 1 5 And

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 whose eccentricity is the reciprocal of the eccentricity of E and whose foci are the same as that of E 2026Passage: Consider the ellipses given by x^2 + 4y^2 = 1 and 4x^2 + y^2 = 1 . Question: Let P be the point in the first quadrant where the given ellipses intersect. If is the acute a 2026Let x^2 f(a^2+7a+3) + y^2 f(3a+15) = 1 represent an ellipse with major axis along y -axis, where f is a strictly decreasing positive function on R . If the set of all possible valu 2026The eccentricity of an ellipse E with centre at the origin O is 3 2 and its directrices are x = 4 6 3 . Let H: x^2 a^2 - y^2 b^2 = 1 be a hyperbola whose eccentricity is equal to t 2026Let x = 9 be a directrix of an ellipse E , whose centre is at the origin and eccentricity is 1 3 . Let P( , 0) , > 0 , be a focus of E and AB be a chord passing through P . Then th 2026Let a focus of the ellipse E: x^2 a^2 + y^2 b^2 = 1 be S(4, 0) and its eccentricity be 4 5 . If the point P(3, ) lies on E and O is the origin, then the area of POS is equal to: 2026Let A be the point (3, 0) and circles with variable diameter AB touch the circle x^2 + y^2 = 36 internally. Let the curve C be the locus of the point B. If the eccentricity of C is 2026Let an ellipse x^2 a^2 + y^2 b^2 = 1 , a < b , pass through the point (4, 3) and have eccentricity 5 3 . Then the length of its latus rectum is : 2026 Full Ellipse list All JEE Advanced PYQs