JEE Main 20238 AprilEvening Shift
- Exam
- JEE Main
- Year
- 2023
- Date
- 8 April
- Shift
- Evening Shift
- Subject
- Mathematics
- Chapter
- Straight Lines
JEE Main 2023 · 8 April · Evening Shift · Mathematics · Straight Lines
Let A ( 0, 1 ) , B ( 1, 1 ) and C ( 1, 0 ) be the mid-points of the...
Let and be the mid-points of the sides of a triangle with incentre at the point . If the focus of the parabola passing through is , where and are rational numbers, then is equal to
Options
- A
- B
- C
- D
Correct answer
A.
Step-by-step solution
Given,
and be the mid-points of the sides of a triangle with incentre at the point ,
Now finding the vertices of the triangle by using midpoint formula and plotting the diagram we get,
Now finding the incentre of the above triangle using the formula,
We get, Incentre
Now given parabola passes through the incentre we get,
Now we know that focus of parabola is given by, focus
Hence, focus will be,\left(\dfrac{1}{4 + 2\sqrt{2}}, 0\right) = \left(\dfrac{4 - 2\sqrt{2}}{8}, 0\right)( \alpha + \beta\sqrt{2}, 0 )\alpha = \dfrac{4}{8} = \dfrac{1}{2}, \beta = - \dfrac{1}{4}\dfrac{\alpha}{{\beta}^{2}} = \dfrac{\dfrac{1}{2}}{{\left(\dfrac{- 1}{4}\right)}^{2}} = \dfrac{16}{2} = 8