Question: If $ \sqrt{2}=1.4142, $ find the value of $ 2\sqrt{2}+\sqrt{2}+\frac{1}{2+\sqrt{2}}-\frac{1}{\sqrt{2}-2} $
Options:
A) 1.4144
B) 2.8284
C) 28.284
D) None of these
Show Answer
Answer:
Correct Answer: D
Solution:
- Expression $ =2\sqrt{2}+\sqrt{2}+\frac{1}{2+\sqrt{2}}-\frac{1}{\sqrt{2}-2} $
$ =3\sqrt{2}+( \frac{1}{2+\sqrt{2}}+\frac{1}{2-\sqrt{2}} ) $
$ =3\sqrt{2}+( \frac{2-\sqrt{2}+2+\sqrt{2}}{(2+\sqrt{2})(2-\sqrt{2})} ) $
$ =3\sqrt{2}+\frac{4}{2} $
$ \Rightarrow $ $ 3\sqrt{2}+2=3\times 1.414+2=6.242 $