Step-by-step explanation:
d = √(x2 - x1)^2 + (y2 - y1)^2 + (z2 - z1)^2
P1(0, 0, 0) P2(-6, 8, 3)
Substitute the values in the above equation and you will get
d = √(-6 - 0)^2 + (8 - 0)^2 + (3 - 0)^2
= √(36 + 64 + 9)
= √109
= 10.44
