Direction Cosines

If a vector makes angles $\alpha, \beta, \gamma$ with axes:

$$ \cos\alpha = \frac{A_x}{\lvert \vec{A} \rvert}, \quad \cos\beta = \frac{A_y}{\lvert \vec{A} \rvert}, \quad \cos\gamma = \frac{A_z}{\lvert \vec{A} \rvert} $$