Show that the function f$($x$)=1-\backslash$sqrt$(1-$x$)$ has the following Taylor

expansion around x$=0$ :

f$($x$)=\backslash$sum$\_($n$=1)^(\backslash$infty $)(((2$n$)/($n$))$x$^($n$))/(4^($n$)(2$n$-1))$