JEE Main 20198 AprilMorning Shift
- Exam
- JEE Main
- Year
- 2019
- Date
- 8 April
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Ellipse
JEE Main 2019 · 8 April · Morning Shift · Mathematics · Ellipse
Let O(0,0) and A(0,1) be two fixed points. Then, the locus of a...
Let and be two fixed points. Then, the locus of a point such that the perimeter of is is
Options
- A
- B
- C
- D
Correct answer
D.
Step-by-step solution
Given,
Locus of is ellipse with foci at & and major
axis \left(2b\right) = 3= 2be = 1 ⇒ e = \dfrac{1}{3}⇒2a = 2b\sqrt{1 - {e}^{2}} = 3 . \dfrac{2\sqrt{2}}{3} = 2\sqrt{2}⇒P\dfrac{{x}^{2}}{8} + \dfrac{{\left(y - \dfrac{1}{2}\right)}^{2}}{9} = \dfrac{1}{4}9{x}^{2} + 8{y}^{2} - 8y = 16