• Always start from O

Basis vectors

• i is the unit vector for x

• j is the unit vector for y

• k is the unit vector for z

Position vectors

• Magnitude is the length of vector (use pythagorus)

• Direction is the angle from the x-axis anti-clock wise

Direction cosines

• Alpha and beta angles, Note: SOHCAHTOA

magnitude, (x,y,z) ← direction cosines

OA = i/magnitude; j/magnitude; k/magnitude