Let P(x1,y1) and Q(x2,y2) be two distinct points on the ellipse
9x2+4y2=1
such that y1>0, and y2>0. Let C denote the circle x2+y2=9, and M be the point ( 3,0 ). Suppose the line x=x1 intersects C at R, and the line x=x2 intersects C at S, such that the y-coordinates of R and S are positive. Let ∠ROM=6π and ∠SOM=3π, where O denotes the origin (0,0). Let ∣XY∣ denote the length of the line segment XY. Then which of the following statements is (are) TRUE?
(A)The equation of the line joining P and Q is 2x+3y=3(1+3)✓ Correct
(B)The equation of the line joining P and Q is 2x+y=3(1+3)
(C)If N2=(x2,0), then 3∣N2Q∣=2∣N2S∣✓ Correct
(D)If N1=(x1,0), then 9∣N1P∣=4∣N1R∣
Answer: (A), (C)
Solution
From the circle x2+y2=9 with ∠ROM=6π and ∠SOM=3π:
R≡(3cos30∘,3sin30∘)=(233,23)
S≡(3cos60∘,3sin60∘)=(23,233)
For the ellipse 9x2+4y2=1 with same x-coordinates:
P≡(233,2sin30∘)=(233,1)
Q≡(23,2sin60∘)=(23,3)
Slope of PQ: m=23−2333−1=−32
Equation: y−3=−32(x−23), simplifying to 2x+3y=3(3+1). (A) ✓
For (C): N2=(23,0), ∣N2Q∣=3, ∣N2S∣=233. So 33=2⋅233 ✓
For (D): N1=(233,0), ∣N1P∣=1, ∣N1R∣=23. So 9⋅1=4⋅23=6 ✗
JEE Advanced · 2025 · 18 May 2025 · Paper 2 · One or more correct options