# Matrix Formulas

 Matrix mult result size; also cols A must equal rows B Matrix transpose Column vector representation Symmetric matrix (X is be any value) Antisymmetric matrix or skew-symmetric matrix (diagonals must be 0) Column vector mult notation (a,b,c cols of M) 2D Matrix determinant Recursive determinant (each is the sub matrix excluding the current col) k is chosen as any row; good when row is mostly zeros Cofactor matrix definition Inverse; adjugate matrix 2D Matrix inverse 3D Matrix inverse 3D matrix inverse (a,b,c cols of M) 4D Matrix inverse. a,b,c,d = 3D column vectors of M. x,y,z,w = last row of M, x = , t = , u = , v =