#P_1->(x_1,y_1,z_1) " the point of "P_1# #P_2->(x_2,y_2,z_2)" the point of "P_2# #Delta x=x_2-x_1=-1+9=8# #Delta y=y_2-y_1=4-3=1# #Delta z=z_2-z_1=-2-1=-3# #"s:distance between the Point of " P_1 " and "P_2"# #s=sqrt(Delta x^2+Delta y^2+Delta z^2)# #s=sqrt(64+1+9)# #s=sqrt 74#