Cross product "matrix", then it can be generalized in an arbitrary number of dimensions. In mechanics, for example, the angular velocity can be interpreted either as a pseudovector formula_167 or as a anti-symmetric matrix or skew-symmetric tensor formula_168. In the latter case, the velocity law for a rigid body looks: where Ω is formally defined from the rotation matrix formula_170 associated to body's frame: formula_171 In three-dimensions holds: In quantum mechanics the angular momentum formula_173 is often represented as an anti-symmetric matrix or tensor. More precisely, it is the result of cross product involving position formula_174 and linear momentum formula_111: Since both
Linear regression linear relationship between the dependent variable and regressors. Thus the model takes the form where denotes the transpose, so that xβ is the inner product between vectors x and β. Often these "n" equations are stacked together and written in matrix notation as where Some remarks on notation and terminology: Example. Consider a situation where a small ball is being tossed up in the air and then we measure its heights of ascent "h" at various moments in time "t". Physics tells us that, ignoring the drag, the relationship can be modeled as where "β" determines the initial velocity of