Question: If a point $ (x,y) $ in $ xy $ -plane is equidistant from $ (-1,1) $ and $ (4,3) $ then
Options:
A) $ 10x+4y=23 $
B) $ 6x+4y=23 $
C) $ -x+y=7 $
D) $ 4x+3y=0 $
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Answer:
Correct Answer: A
Solution:
- Distance between $ (x,y) $ and $ (-1,1) $
$ =\sqrt{{{(y-1)}^{2}}+{{(x+1)}^{2}}} $
Distance between $ (x,y) $ and $ (4,3) $
$ =\sqrt{{{(y-3)}^{2}}+{{(x-4)}^{2}}} $
$ \because $ Point are equidistant
$ =\sqrt{{{(y-1)}^{2}}+{{(x+1)}^{2}}}=\sqrt{{{(y-3)}^{2}}+{{(x-4)}^{2}}} $
On squaring both side, we get
$ {{(y-1)}^{2}}+{{(x+1)}^{2}}={{(y-3)}^{2}}+{{(x-4)}^{2}} $
$ \Rightarrow $ $ y^{2}+1-2y+x^{2}+1+2x $
$ =y^{2}+9-6y+x^{2}+16-8x $
$ \Rightarrow $ $ 2x-2y+2=-6y-8x+25 $
$ \therefore $ $ 10x+4y=23 $