Quantitative Aptitude Ques 1110
Question: Value of $ \sqrt{-\sqrt{5}+\sqrt{1+4\sqrt{9+4\sqrt{5}}}} $ is
Options:
A) $ \sqrt{2} $
B) $ \sqrt{3} $
C) $ 2 $
D) $ \sqrt{5} $
Show Answer
Answer:
Correct Answer: A
Solution:
- $ \sqrt{-\sqrt{5}\sqrt{1+4\sqrt{9+4\sqrt{5}}}} $
$ =\sqrt{-\sqrt{5}+\sqrt{1+4\sqrt{{{(2)}^{2}}+{{(\sqrt{5})}^{2}}+2\times 2\sqrt{5}}}} $
$ =\sqrt{-\sqrt{5}+\sqrt{1+4\sqrt{{{(2+\sqrt{5})}^{2}}}}} $
$ =\sqrt{-\sqrt{5}+\sqrt{1+4,(2+\sqrt{5})}} $
$ =\sqrt{-\sqrt{5}+\sqrt{9+4\sqrt{5}}} $
$ =\sqrt{-\sqrt{5}+(2+\sqrt{5})}=\sqrt{2} $