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David J. Krus presents Matrix Algebra for Social Sciences. Introduction to Matrix Algebra. Dimensions of a Matrix. Number of Rows: 2 Number of Columns:3 A 2 x 3 Matrix. Elements of a Matrix. Principal Diagonal Elements . Off-Diagonal Elements . Nomenclature of Matrices. Rectangular
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Dimensions of a Matrix • Number of Rows: 2 • Number of Columns:3 • A 2 x 3 Matrix
Nomenclature of Matrices • Rectangular • Square • Symmetric • Skew Symmetric
Matrix Algebra Operations on Matrix Elements
Addition of Matrix Elements • All matrices must have the the same dimensions. • The plus sign is enclosed in parentheses. 2 x 2 2 x 2 2 x 2
Subtraction of Matrix Elements • All matrices must have the the same dimensions. • The subtraction sign is enclosed in parentheses. 2 x 2 2 x 2 2 x 2
Multiplication of Matrix Elements • All matrices must have the the same dimensions. • The multiplication sign is enclosed in parentheses. 2 x 2 2 x 2 2 x 2
Division of Matrix Elements • All matrices must have the the same dimensions or the divisor must be a scalar number. • The division sign is enclosed in parentheses. 2 x 2 2 x 2 2 x 2
Powers of Matrix Elements • The square sign is enclosed in parentheses.
Powers of Matrix Elements • The square sign is enclosed in parentheses
Matrix Algebra Operations on Matrices
Addition of Matrices 3 x 1 1 x 3 3 x 3
Major Addition of Matrices 1 + 1 = 2 1 + 2 = 3 1 + 3 = 4
Major Addition of Matrices 2 + 1 = 3 2 + 2 = 4 2 + 3 = 5
Major Addition of Matrices 3 + 1 = 4 3 + 2 = 5 3 + 3 = 6
Minor Addition of Matrices (1+1) + (2+2) + (3+3) = 12
Subtraction of Matrices 1 x 3 3 x 1 1 x 1
Minor Subtraction of Matrices (1-1) + (2-2) + (3-3) =0
Major Subtraction of Matrices 1 - 1 = 0 1 - 2 = -1 1 - 3 = -2
Major Subtraction of Matrices 2 - 1 = 1 2 - 2 = 0 2 - 3 = -1
Major Subtraction of Matrices 3 - 1 = 2 3 - 2 = 1 3 - 3 = 0
Multiplication of Matrices 3 x 2 2 x 3 3 x 3
Multiplication of Matrices (1*7) + (2*10) =27 (1*8) + (2*11) =30 (1*9) + (2*12) =33
Multiplication of Matrices (3*7) + (4*10) = 61 (3*8) + (4*11) = 68 (3*9) + (4*12) = 75
Multiplication of Matrices (5*7) + (6*10) = 95 (5*8) + (6*11) = 106 (5*9) + (6*12) = 117
Powers of Matrices (1*1) + (2*3) = 7 (1*2) + (2*4) = 10 (3*1) + (4*3) = 15 (3*2) + (4*4) = 22
Algebraic Mean In Summation Notation
Algebraic Mean In Matrix Algebra Notation
True Variance In Summation Notation
True Variance In Matrix Algebra Notation