Answer
It is not possible to compute the given expression
Work Step by Step
Since A is a $3 \times 2$ matrix, so $t^3.A(t)$ will be $3\times 2$ matrix.
The same for $B$ matrix. Since $B$ is a $4 \times 2$ matrix, so $-\sin tB$ will also be $4 \times 2$ matrix.
Hence, it is not possible to compute the given expression.
