Question 3: Two beams on a construction site can be described as

s1 = {x = 1 - 2t, y = 2 + 6t, z = 4 - 8t 0 ≤ t ≤ 5

and

s2 = {x = 12 + 2t, y = 4 + t, z = -8 + t -10 ≤ t ≤ 10

These two beams are to be be connected by a third beam that is perpendicular to both s1 and s2. In what points on s1 and s2 should the third beam be attached?