Answer
See below
Work Step by Step
$T_1:M_n(R) \rightarrow M_n(R) \\
T_2:M_n(R) \rightarrow M_n(R)$
We obtain:
$(T_2T_1)(A)=T_2(T_1(A))\\
=T_2(A-A^T)\\
=A-A^T+(A-A^T)^T\\
=A-A^T+A^T-(A^T)^T\\
=A-A^T+A^T-A\\
=0$
Hence, $T_2T_1$ is a zero transformation.
