The plane P1 passes through the P, with position vector i + 2j – k, and is perpendicular to the line L with equation
r = 3i – 2k +l(-i + 2j + 3k)
They got the normal to the plane to be : – i + 5j + 3k
How did they get that? Thanks in advance.
(Sorry for the strange font, I can't be bothered to edit the font.)