Question: The area of the region bounded by the locus of a point P satisfying  $ d(P,A)=4 $ , where A is (1, 2) is
Options:
A) 64 sq. unit
B) 54 sq. unit
C)  $ 16\pi sq.unit $
D) None of these
  Show Answer
  Answer:
Correct Answer: A
Solution:
- [a] We have, max  $ { |x-1|, |y-2| } = 4 $
If  $ { |x-1| \ge |y-2| }, $
then  $ | x-1 |=4, $
i.e., if  $ (x+y-3)(x-y+1)\ge 0, $
Then  $ x = -3 \text{ or } 5, $
If  $ | y-2 |\ge | x-1 |, $
Then  $ | y-2 |=4 $
i.e.,  $ (x+y-3)(x-y+1)\le 0, $
Then  $ y = -2 \text{ or } 6 $.
So, the locus of P bounds a square, the equation of whose sides are  $ x=-3,x=5,y=-2,y=6 $
Thus, the area is  $ {{(8)}^{2}}=64. $