JEE Main 2020
Conic Sections
Parabola
Hard
Question
Let be the circle of minimum area touching the parabola and the lines . Then, which one of the following points lies on the circle ?
Options
Solution
This problem requires a strong understanding of geometric properties, especially tangency conditions for circles with lines and parabolas, combined with an appreciation for symmetry to simplify the problem. The goal is to find the circle of minimum area, which implies finding the circle with the minimum radius.
1. Understanding the Geometry and Initial Symmetry Analysis
The problem involves a parabola and two lines. Let's analyze their properties:
- Parabola: . This is a downward-opening parabola with its vertex at . It is symmetric about the y-axis.
- Lines: represents two lines: