JEE Advanced2016MathematicsStraight LinesActual
Paragraph: Let F₁ (x₁, 0 ) and F₂ (x₂, 0 ) , for x₁ 0 , be the foci of the ellipse x² 9 + y² 8 =1 . Suppose a parabola having vertex at the origin and focus at F₂ intersects the ellipse at point M in the first quadrant and at point N in the fourth quadrant. Question: The orthocentre of the triangle F₁ M N is
Options
- A- 9 10 ,   0
- B2 3 ,   0
- C9 10 ,   0
- D2 3 ,   6
Correct answer
A. - 9 10 ,   0
Step-by-step solution
x 2 9 + y 2 8 = 1 F 1 ( − 1 , 0 ) , F 2 ( 1 , 0 ) ⇒ Parabola is y 2 = 4 x The intersection of ellipse & parabola is M   &   N x 2 9 + 4 x 8 = 1 ⇒ M ( 3 2 , 6 )   &     N ( 3 2 , − 6 ) Equation of altitude through M   : y -   6 = 5 2 6   x - 3 2 Equation of altitude through F 1 : y = 0 Solving, we get orthocentre - 9 10 ,   0