Find a vector that is normal to the plane containing the lines L1, and L2, whose equatiosn are:?

Question

L1 : r = i + j + x (2i + j -2k)

L2: r = 3i +2j + u (j+3k)

Answer 1

get the cross product of the direction vectors of the lines .. . .

line 1: direction vector: N1 = 〈 2 , 1 , -2 〉

line 2: direction vector: N2

answer: N1 x N2

.. . .. .

Theorem: the cross product is the vector that is perpendicular to both the original two vectors