Question
If $\sqrt2=1.4142,$ then $\sqrt{\frac{\sqrt2-1}{\sqrt2+1}}$ is equal to:
✓
Answer
- 0.4142
Solution:
By Rationalising $\frac{\sqrt2-1}{\sqrt2+1},$ we get
$\frac{\sqrt2-1}{\sqrt2+1}\times\frac{\sqrt2-1}{\sqrt2-1}=\frac{\big(\sqrt2-1\big)^2}{\big(\sqrt2\big)^2-1^2}=\frac{\big(\sqrt2-1\big)^2}{1}$
So $\sqrt{\frac{\sqrt2-1}{\sqrt2+1}}=\sqrt{\frac{\big(\sqrt2-1\big)^2}{1}}\\ \ =\big(\sqrt2-1\big)=1.4142-1=0.4142$
Hence, correct option is (c).
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