3.2.1
Das Skalarprodukt muss 0 sein
[2, k, 3]·[-2, 5, 1] = 0 --> k = 0.2
3.2.2
Gleichsetzen
[6, -12, 9] + r·[2, 0, 3] = [-4, 3, 6] + s·[-2, 5, 1] --> r = -2 ∧ s = -3
[6, -12, 9] - 2·[2, 0, 3] = [2, -12, 3]
Winkel
ACOS([2, 0, 3]·[-2, 5, 1]/(ABS([2, 0, 3])·ABS([-2, 5, 1]))) = 92.90°