Identification of Conic Sections from Loci and Parametric Forms
Match the conics in Column I with the statements/expressions in Column II.
Options
(A) (p)
(B) (s), (t)
(C) (r)
(D) (q), (s)
Topics & Concepts
Step-by-Step Solution
To determine the correct matches between Column I and Column II, we analyze each statement in Column II step-by-step:
1. Statement (p)
The line is given by and it touches the circle (radius , center ).
The perpendicular distance from the center to the line is equal to the radius:
Replacing with , the locus is:
This is the equation of a Circle.
Hence, (A) (p).
2. Statement (q)
The given condition in the complex plane is:
Let the two fixed points (foci) be and .
The distance between the foci is .
The locus represents points such that the absolute difference between their distances to the two fixed points is constant:
Since , we have the eccentricity .
This defines a Hyperbola.
Hence, (D) (q).
3. Statement (r)
The parametric equations are:
Substituting , we use the standard half-angle identities and to get:
Eliminating the parameter :
This is the standard equation of an Ellipse.
Hence, (C) (r).
4. Statement (s)
The eccentricity of the conic lies in the interval:
- For a Parabola, the eccentricity is .
- For a Hyperbola, the eccentricity is , which also lies in .
Hence, (B) (s) and (D) (s).
5. Statement (t)
Let . Then:
Taking the real part:
The right-hand side is:
Equating both sides:
This is the equation of a Parabola.
Hence, (B) (t).
Conclusion:
- (A) (p)
- (B) (s), (t)
- (C) (r)
- (D) (q), (s)
All the given options A, B, C, and D are correct.