\(AB = \sqrt {{{\left( {{x_B} - {x_A}} \right)}^2} + {{\left( {{y_B} - {y_A}} \right)}^2} + {{\left( {{z_B} - {z_A}} \right)}^2}} \)

\(AB = \sqrt {{{\left( {{x_B} + {x_A}} \right)}^2} + {{\left( {{y_B} + {y_A}} \right)}^2} + {{\left( {{z_B} + {z_A}} \right)}^2}} \)

\(AB = {\left( {{x_B} - {x_A}} \right)^2} + {\left( {{y_B} - {y_A}} \right)^2} + {\left( {{z_B} - {z_A}} \right)^2}\)     

$AB = {\sqrt {\left( {{x_B} - {x_A}} \right)} ^2} + {\sqrt {\left( {{y_B} - {y_A}} \right)} ^2} + {\sqrt {\left( {{z_B} - {z_A}} \right)} ^2}$