Maclaurin series question

Hi All, help much appreciated!

These are the steps to determine the first two terms in a maclaurin series,

but they are the same so my working must be out? Its spread over 2 posts cos of laTex limit!

$\displaystyle

\begin{gathered}

\ln \frac{1}

{{\sqrt {1 - x} }} \hfill \\

f(x) = \ln (1 - x)^{ - 1/2} \hfill \\

f(0) = 0 \hfill \\

f'(x) = \frac{1}

{{(1 - x)^{ - 1/2} }}.\frac{{ - 1(1 - x)^{ - 3/2} .( - 1)}}

{2} \hfill \\

f'(x) = \frac{{(1 - x)^{ - 1} }}

{2} \hfill \\

\end{gathered}

$