die g hat die Gleichung
\(\overrightarrow{x}\) = [-2, 4, 9] + r * ( [4, -2, 3] - [-2, 4, 9] ) = [-2, 4, 9] + r * [6, -6, -6]
z-Koordinate 9 - 6rs = 0 → rs = 3/2
rs in g → \(\overrightarrow{x_s}\) = [-2, 4, 9] + 3/2 * [6, -6, -6] = [7, -5, 0]
→ gesuchter Spurpunkt S(7|-5)|0)
Gruß Wolfgang