JEE Main 2021
Conic Sections
Parabola
Medium
Question
Let L 1 be a tangent to the parabola y 2 = 4(x + 1) and L 2 be a tangent to the parabola y 2 = 8(x + 2) such that L 1 and L 2 intersect at right angles. Then L 1 and L 2 meet on the straight line :
Options
Solution
Key Concepts: Equation of Tangent to a Parabola and Conditions for Perpendicular Lines
The core of this problem involves two main mathematical concepts:
- Equation of Tangent to a Parabola: For a standard parabola in the form , the equation of a tangent line with a slope is given by: This formula is incredibly versatile. When a parabola is shifted, for example, from to , we simply replace the standard coordinate with the shifted coordinate in the general tangent equation. If the coordinate is also shifted, say to , then $