PlanetPhysics/Dot Product

The dot product or scalar product is defined as

$$ \mathbf{A} \cdot \mathbf{B} = A_x B_x + A_y B_y + A_z B_z $$

{\mathbf Geometric interpretation}

Using a geometric interpretation allows us to find the angle between two vectors because

$$ \mathbf{A} \cdot \mathbf{B} = \left | \mathbf{A} \right | \left | \mathbf{B} \right | \cos \theta$$

It is also useful to note that if the two vectors are perpindicular, their dot product is zero since

$$ \cos \left (90^o \right) = 0$$