Quantitative Aptitude Ques 1799
Question: If the distance of the point $ P(x,y) $ from $ A(a,0) $ is $ a+x, $ then $ y^{2} $ is equal to
Options:
A) $ 2ax $
B) $ 4ax $
C) $ 6ax $
D) $ 8ax $
E) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
- Given, $ AP=a+x $
$ \Rightarrow $ $ \sqrt{{{(x-a)}^{2}}+{{(y-0)}^{2}}}=a+x $ On squaring both sides, we get $ {{(x-a)}^{2}}+y^{2}={{(a+x)}^{2}} $
$ \Rightarrow $ $ x^{2}+a^{2}-2ax+y^{2}=a^{2}+2ax+x^{2} $
$ \Rightarrow $ $ x^{2}+a^{2}+y^{2}-a^{2}-x^{2}=2ax+2ax $
$ \Rightarrow $ $ y^{2}=4ax $
BETA
