JEE Main 2023
Conic Sections
Parabola
Hard
Question
Let PQ be a focal chord of length 6.25 units of the parabola y 2 = 4x. If O is the vertex of the parabola, then 10 times the area (in sq. units) of POQ is equal to ___________.
Answer: 2
Solution
This solution will guide you through calculating the area of a triangle formed by the vertex and the endpoints of a focal chord of a parabola. We will systematically use the properties of parabolas and focal chords to find the necessary parameters and then apply the area formula.
1. Key Concept: Area of a Triangle with Vertex at Origin
The fundamental concept we will use is the formula for the area of a triangle when one of its vertices is at the origin. Given three vertices , , and , the area of is given by: