Determine whether the planes are parallel or orthogonal.

Equations given:
5x - 3y + z = 4
x + 4y + 7z = 1

How exactly do I solve this? It wasn't covered completely in class.

1 answer

The normals of the two planes are
(5, -3, 1) and (1 , 4, 7)

Since one is not a multiple of the other, the two planes cannot be parallel

if they are orthogonal (perpendicular) then their dot product must be zero

so (5,-3,1)∙(1,4,7) = 5 -12 + 7 = 0
YEs, they are orthogonal