Finding a Vector Perpendicular to Two Given Vectors

Supposeis perpendicular to bothandThenandWe obtain the equations

(1)

(2)

gives

gives

The vectoris then perpendicular to bothandWe can multiply this vector by the scalarobtaining(3) and the result will still be perpendicular.

(3) is important enough to be gaven a name. It is the vector or cross product ofand