dual in German

(grammar) Pertaining to a grammatical number in certain languages that refers to two of something, such as a pair of shoes.

(mathematics) Of a vector in an inner product space, the linear functional corresponding to taking the inner product with that vector. The set of all duals is a vector space called the dual space.

(mathematics) Of a vector in an inner product space, the linear functional corresponding to taking the inner product with that vector. The set of all duals is a vector space called the dual space.