Binomial approximations

An expression of the form:

\[ (1 + x)^{n} \]

where \(|x| < 1\) and \(n\) is a non-integer, can be approximated using sufficiently many terms of the expression:

\[ 1 + nx + n(n-1)\frac{x^{2}}{2!} + n(n-1)(n-2)\frac{x^{3}}{3!} + ... \]

Examples

Expression \(1\) \(x\) \(x^{2}\) \(x^{3}\)
\((1 + x)^{\frac{1}{2}}\) \(1\) \(\frac{1}{2}\) \(-\frac{1}{8}\) \(\frac{1}{16}\)
\(1 - \sqrt{1 - x}\) \(0\) \(\frac{1}{2}\) \(-\frac{1}{8}\) \(\frac{1}{16}\)
\((1+x)^{-\frac{1}{2}}\) \(1\) \(-\frac{1}{2}\) \(\frac{3}{8}\) \(-\frac{5}{16}\)
\((1 - 2x^{2})^{-\frac{1}{2}}\) \(1\) \(0\) \(1\) \(0\)