Question

Picture will help

Answer 1

Im unsure if i've done it correct so far

Answer 2

write it as
\[ \left( 1+ (-t^4)\right)^{- \frac{1}{2}} \\

\]
\[=\sum_{n=0}^{\infty}\left(\begin{matrix}-\frac{ 1 }{ 2 } \\ n\end{matrix}\right)\left(-t^4\right)^n\]