Question

if A=3i +j+2k and B=2i-2j+4k then value of a*b is​

Answer 1

ANSWER

To find a vector perpendicular to both A and B, just compute A x B (the cross product).

That vector won't be a unit vector, but if you compute its length, then you can just divide by that number and you'll end up with a unit vector perpendicular to both A and B.

In other words:

The vector you want is (A x B) / || A x B ||.

To find the angle between A and B, use the fact that A . B = ||A|| ||B|| cos (theta), where . denotes dot product and theta is the angle between the two vectors.

Answer 2

Answer:

To find a vector perpendicular to both A and B, just compute A x B (the cross product).

That vector won't be a unit vector, but if you compute its length, then you can just divide by that number and you'll end up with a unit vector perpendicular to both A and B.

In other words:

The vector you want is (A x B) / || A x B ||.

To find the angle between A and B, use the fact that A . B = ||A|| ||B|| cos (theta), where . denotes dot product and theta is the angle between the two vectors.