\(\,{\rm{A}}\,\, = \,\,\sqrt {{{\rm{A}}_{\rm{x}}}^2\,\, + \;\,{A_y}^2\,\, + \;\;{A_z}^2} \,\, = \,\,\sqrt {1\,\, + \,\,1\,\, + \;\;1} \,\, = \,\,\,\sqrt {\rm{3}} \)

\({\rm{cos}}\,\,\alpha \,\, = \,\,\frac{{{{\rm{A}}_{\rm{x}}}}}{{\rm{A}}}\,\, = \,\,\frac{1}{{\sqrt 3 }}\)

\(\cos \,\,\beta \,\, = \,\,\frac{{{A_y}}}{A}\,\, = \,\,\frac{1}{{\sqrt 3 }}\)

\(\cos \,\gamma \,\, = \,\,\frac{{{A_z}}}{A}\,\, = \,\,\frac{1}{{\sqrt 3 }}\)