Coordinate Geometry Question 95
Question: The coordinates of the points A and B are (a, 0) and $ (-a,0) $ respectively. If a point P moves so that $ PA^{2}-PB^{2}=2k^{2} $ , when k is constant, then the equation to the locus of the point P , is
Options:
A) $ 2ax-k^{2}=0 $
B) $ 2ax+k^{2}=0 $
C) $ 2ay-k^{2}=0 $
D) $ 2ay+k^{2}=0 $
Show Answer
Answer:
Correct Answer: B
Solution:
Let the point be (x, y), Then $ {{(x-a)}^{2}}+y^{2}-{{(x+a)}^{2}}-y^{2}=2k^{2} $
$ \Rightarrow -4ax-2k^{2}=0\Rightarrow 2ax+k^{2}=0 $ .
BETA
