Which among the following is NOT correct statement about $$\mathrm{S_N1}$$ reaction?

Identify reductant in following reaction.

$$\mathrm{{C_2}O_4^{2 - } + MnO_4^ - + {H^ + } \longrightarrow M{n^{2 + }} + C{O_2} + {H_2}O}$$

$$\int \tan ^{-1}(\sec x+\tan x) d x=$$

$$A(\propto)=\left[\begin{array}{cc}\cos \propto & \sin \propto \\ -\sin \propto & \cos \propto\end{array}\right]$$, then $$\left[A^2(\propto)\right]^{-1}=$$