If $D$ is the domain and $G$ is the range of the real valued function $f(x)=\sqrt{\frac{1-x^2}{1+x^2}}$, then $D \cap G=$

Let $A=\left[\begin{array}{ll}0 & 1 \\ 1 & k\end{array}\right], k \in R$ and $A^3=\left[\begin{array}{ll}a & b \\ c & d\end{array}\right]$. If $d=228$, then $b+c=$

Let $A$ and $B$ be two $3 \times 3$ matrices and $C$ be a $3 \times 3$ unit matrix such that $A B-C$ is a non-singular matrix. Let $D=(A B-C)^{-1}$. Then, consider the following statements.

Statement I $\operatorname{det}(B A)=\operatorname{det}(B A-C) \operatorname{det}(B D A)$

Statement II $A B D=D A B$

Which of the above statements is (are) true?

Let $A=\left[\begin{array}{ccc}0 & 0 & -1 \\ 0 & -1 & 0 \\ -1 & 0 & 0\end{array}\right], B=\left[\begin{array}{lll}0 & 1 & 0 \\ 1 & 0 & 0 \\ 0 & 0 & 1\end{array}\right]$, then $\left(A^{-1} B\right)^{-1}+\left(A B^{-1}\right)^{-1}=$