Let $A \in \mathbb{F}^{p \times q}$ and suppose that $\mathcal{R}_A=\mathbb{F}^p$ and $\mathcal{N}_A \dot{+} \mathcal{Y}=$ $\mathbb{F}^q$ for some proper nonzero subspace $\mathcal{Y}$ of $\mathbb{F}^q$. Show that there exists a pseudoinverse $A^{\circ}$ of $A$ such that $\mathcal{N}_{A^{\circ}}=\{\mathbf{0}\}$ and $\mathcal{R}_{A^{\circ}}=\mathcal{Y}$.