QuestionLet V={[abcd]∈M2×2(R):a+b=c+d}V=\left\{\begin{bmatrix}a&b\\c&d\end{bmatrix}\in M_{2\times2}(\mathbb{R}):a+b=c+d\right\} and T:V→R2T:V\to\mathbb{R}^2 be onto. What is the dimension of ker(T)\ker(T)?
