'''Geometrically:''': The Dot Product of two unit-length vectors is defined to be the cosine of the angle between them. For more general vectors, the Dot Product is defined to be linear in vector lengths. '''Algebraically:''': The Dot Product of two vectors is the sum of the products of corresponding terms. '''Examples:''' * [1,2].[4,5] = 1*4+2*5 = 14 * [1,2,3].[-3,6,-3] = 0 ** This shows that geometrically these two vectors are perpendicular. The connection between the algebraic and geometric interpretations leads to some extremely useful methods of calculation. See also: * http://mathworld.wolfram.com/DotProduct.html * DotProductInManyProgrammingLanguages ---- CategoryMath