Augustine Bannatyne - Leudar

Can someone show me how to do the follwing equation in expr object :

http://mathsfirst.massey.ac.nz/Algebra/PythagorasTheorem/images/pa2.gif

whereby the X,Y,Z are $1s and I get the "PQ" as an output. Im basically trying to get the distance between two moving ponts in 3D space

whereby the X,Y,Z  are $1s and I get the "PQ" as an output. Im basically trying to get the distance between two moving ponts in 3D space
thanks

Can someone show me how to do the follwing equation in expr object :
http://mathsfirst.massey.ac.nz/Algebra/PythagorasTheorem/images/pa2.gif

Pythagorean equation in Max