The number of points of intersection of ∣z−(4+3i)∣=2 and ∣z∣+∣z−4∣=6,z∈C is :
(A)0
(B)1
(C)2✓ Correct
(D)3
Answer: (C)
Solution
The first equation ∣z−(4+3i)∣=2 represents a circle with center (4,3) and radius 2. The second equation ∣z∣+∣z−4∣=6 represents an ellipse with foci at (0,0) and (4,0), where 2a=6 so a=3, c=2, and b2=a2−c2=5. The ellipse equation is 9(x−2)2+5y2=1.
The lower extremity of the vertical diameter of the circle is at (4,1). Substituting into the ellipse equation: 9(4−2)2+51=94+51=4529<1. Since this point lies inside the ellipse, and the circle has radius 2, the circle intersects the ellipse at exactly 2 points.
Answer: (C)
JEE Main · 2022 · 27 Jun 2022 · Shift 2 · Single correct option