# Scalar product

From AMS Glossary

(Redirected from Direct product)

## scalar product

(

*Also called*dot product, direct product, inner product.) A scalar equal to the product of the magnitudes of any two vectors and the cosine of the angle θ between their positive directions.For two vectors If a scalar product is zero, one of the vectors is zero or else the two are perpendicular.

**A**and**B**, the scalar product is most commonly written**A**·**B**, read "**A**dot**B**," and occasionally as (**AB**). If the vectors**A**and**B**have the components*A*_{x},*B*_{x},*A*_{y},*B*_{y}, and*A*_{z},*B*_{z}along rectangular Cartesian*x*,*y*, and*z*axes, respectively, then*See*vector product.