Locus of the image of the point in the line , is a :
- (A)straight line parallel to -axis.
- (B)circle of radius .✓ Correct
- (C)circle of radius .
- (D)straight line parallel to -axis.
Answer: (B)
Solution
Every line in the family passes through the fixed point where and meet, namely . Reflecting the fixed point across a line that pivots about keeps the image a constant distance from , equal to the distance between and . That distance is , so the image traces a circle of radius .
JEE Main · 2015 · 04 Apr 2015 · Offline · Single correct option