Let $f,g:R \rightarrow $R be defined by $f(x)=2x+1$ and $g(x)=x^2-2,\forall x \in R,$respectively. Then, find $g\;of(x)$.

Question

$\begin{array}{1 1} 4x^2 -4x -1 \\ 4x^2+4x-1 \\ 4x^2+4x +1 \\ 4x^2-4x+1 \end{array}$