Trace (linear algebra)In linear algebra, the trace of a square matrix A, denoted tr(A), is defined to be the sum of elements on the main diagonal (from the upper left to the lower right) of A. The trace is only defined for a square matrix (n × n). It can be proven that the trace of a matrix is the sum of its (complex) eigenvalues (counted with multiplicities). It can also be proven that tr(AB) = tr(BA) for any two matrices A and B. This implies that similar matrices have the same trace.
Multiracial peopleMultiracial people or mixed-race people are people of more than one race. A variety of terms have been used both historically and presently for mixed race people in a variety of contexts, including multiethnic, polyethnic, occasionally bi-ethnic, Métis, Muwallad, Colored, Dougla, half-caste, ʻafakasi, mestizo, mutt, Melungeon, quadroon, octoroon, sambo/zambo, Eurasian, hapa, hāfu, Garifuna, pardo, and Gurans. A number of these terms are now considered offensive, in addition to those that were initially coined for pejorative use.