#In Exercises 21 – 24, write out the first 5 terms of the Binomial series with the given k-value.

21. \(k = \frac{1}{2}\):

The Binomial series with \(k = \frac{1}{2}\) expands as:

\[ (1 + x)^{\frac{1}{2}} = 1 + \frac{1}{2}x - \frac{1}{8}x^2 + \frac{1}{16}x^3 - \frac{5}{128}x^4 + \cdots \]

So, the first five terms are:

\[ 1 + \frac{1}{2}x - \frac{1}{8}x^2 + \frac{1}{16}x^3 - \frac{5}{128}x^4 \]

22. \(k = -\frac{1}{2}\):

The Binomial series for \((1 + x)^{-\frac{1}{2}}\) expands as:

\[ (1 + x)^{-\frac{1}{2}} = 1 - \frac{1}{2}x - \frac{1}{8}x^2 - \frac{1}{16}x^3 - \frac{5}{128}x^4 - \cdots \]

So, the first five terms are:

\[ 1 - \frac{1}{2}x - \frac{1}{8}x^2 - \frac{1}{16}x^3 - \frac{5}{128}x^4 \]

23. \(k = \frac{1}{3}\):

The Binomial series for \((1 + x)^{\frac{1}{3}}\) expands as:

\[ (1 + x)^{\frac{1}{3}} = 1 + \frac{1}{3}x - \frac{1}{9}x^2 + \frac{5}{81}x^3 - \frac{5}{243}x^4 + \cdots \]

So, the first five terms are:

\[ 1 + \frac{1}{3}x - \frac{1}{9}x^2 + \frac{5}{81}x^3 - \frac{5}{243}x^4 \]

24. \(k = 4\):

The Binomial series for \((1 + x)^{4}\) expands as:

\[ (1 + x)^{4} = 1 + 4x + 6x^2 + 4x^3 + x^4 + \cdots \]

So, the first five terms are:

\[ 1 + 4x + 6x^2 + 4x^3 + x^4 \]