The domain and range of a real valued function $f(x)=\cos x-3$ are respectively

If $f: R \rightarrow R$ and $g: R \rightarrow R$ are two functions defined by $f(x)=2 x-3$ and $g(x)=5 x^2-2$, then the least value of the function $(g \circ f)(x)$ is

If $A$ and $B$ are both $3 \times 3$ matrices, then which of the following statements are true?

(i) $A B=0 \Rightarrow A=0$ or $B=0$

(ii) $A B=I_3 \Rightarrow A^{-1}=B$

(iii) $(A-B)^2=A^2-2 A B+B^2$