If $a$, $b$, and $c$ are the $p^{th}$, $q^{th}$, and $r^{th}$ terms of a Harmonic Progression (HP), then the vectors $\vec{u} = \frac{\hat{i}}{a} + \frac{\hat{j}}{b} + \frac{\hat{k}}{c}$ and $\vec{v} = (q - r)\hat{i} + (r - p)\hat{j} + (p - q)\hat{k}$: