6. Let [tex]M_{2 \times 2}[/tex] be the vector space of all [tex]2 \times 2[/tex] matrices. Define [tex]T: M_{2 \times 2} \rightarrow M_{2 \times 2}[/tex] by [tex]T(A)=A+A^T[/tex]. For example, if [tex]A=\left[[tex][tex]\begin{array}{ll}a & b \\ c & d\end{array}\right][/tex], then [tex]T(A)=\left[\begin{array}{cc}2 a & b+c \\ b+c & 2 d\end{array}\right][/tex].[/tex][/tex]
(i) Prove that [tex]T[/tex] is a linear transformation.
(ii) Let [tex]B[/tex] be any element of [tex]M_{2 \times 2}[/tex] such that [tex]B^T=B[/tex]. Find an [tex]A[/tex] in [tex]M_{2 \times 2}[/tex] such that [tex]T(A)=B[/tex]
(iii) Prove that the range of [tex]T[/tex] is the set of [tex]B[/tex] in [tex]M_{2 \times 2}[/tex] with the property that [tex]B^T=B[/tex]
(iv) Find a matrix which spans the kernel of [tex]T[/tex].