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Math 3 Warm Up 8/19/13. 1. 2. 1. 2. Identity Matrix. Aug. 19, 2013. Identity Matrix. Capital I represents the identity matrix A square matrix The main (principal) diagonal (upper left to lower right) is all ones All other elements are 0 What is it in the real number system?
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Math 3 Warm Up 8/19/13 1. 2.
Identity Matrix Aug. 19, 2013
Identity Matrix • Capital I represents the identity matrix • A square matrix • The main (principal) diagonal (upper left to lower right) is all ones • All other elements are 0 • What is it in the real number system? • ?
Identity Matrix I for a 3 x 3 matrix : What is I for a 2 x 2 matrix? For a 4 x 4 matrix?
Inverse Matrix Aug. 19, 2013
Inverse Matrix • The inverse of matrix A is denoted as . • You can only find the inverse of a square matrix • What is a square matrix? • The inverse matrix is the multiplicative inverse of the matrix • What is a multiplicative inverse? • No row can be a multiple of another row • Determinant ≠ 0 (If determinant = 0 then the matrix doesn’t have an inverse.)
How do you find ? (switch & change)