Given that PQ→=-i+2j-2k, the magnitude of PQ→ is
The magnitude of a vector PQ→ is given by ||PQ→|| = √((Px - Qx)^2 + (Py - Qy)^2 + (Pz - Qz)^2), where P and Q are the coordinates of the vector PQ→.
In this case, P = -i + 2j - 2k and Q = 0.
Substituting these values into the magnitude formula, we get:
||PQ→|| = √(((-1) - 0)^2 + (2 - 0)^2 + (-2 - 0)^2)
= √(1 + 4 + 4)
= √9
= 3
Therefore, the magnitude of PQ→ is 3.