railway RRB NTPC Mock Test Series 2024-25 (CBT 1 + CBT 2) Quantitative Aptitude Simplification Surds and Indices
If \(a = \frac{{\sqrt 2 + 1}}{{\sqrt 2 - 1}}\) and \( b = \;\frac{{\sqrt 2 + 1}}{{\sqrt 2 - 1}},\) then the value of \(\frac{{{a^3}\; - \;{b^3}}}{{3ab\left( {a + b} \right)}} + \frac{b}{a} - a = \)
1
\(\frac{1}{{\sqrt 2 - 1}}\)
2
\(\frac{2}{{\sqrt 2 - 1}}\)
3
\(\frac{{ - 2}}{{\sqrt 2 - 1}}\)
4
\(\frac{{ - 1}}{{\sqrt 2 - 1}}\)