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A. domain. range. A -1. MATRIX INVERSE. Pamela Leutwyler. For every vector v , I v = v. I. A Square matrix with 1’s on the diagonal and 0’s elsewhere Is called an IDENTITY MATRIX. A square matrix A has an inverse if there is a matrix A -1 such that: AA -1 = I. P. R.
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A domain range A-1 MATRIX INVERSE Pamela Leutwyler
For every vector v, I v = v I A Square matrix with 1’s on the diagonal and 0’s elsewhere Is called an IDENTITY MATRIX.
A square matrix A has an inverse if there is a matrix A-1 such that: AA-1 = I
P R R R v v v v v v v v v If you know the value of You can find because Rotation is 1 – 1 (invertible) w w Only one to one mappings can be inverted: Is the projection of onto Is the counterclockwise Rotation of through degrees.
R R R P v v v v v v v v v v v v If you know the value of You can find because Rotation is 1 – 1 (invertible) Given P v , w w Only one to one mappings can be inverted: Is the projection of onto Is the counterclockwise Rotation of through degrees. P is NOT invertible P is NOT 1-1. v could be any one of many vectors
Now we will develop an algorithm to find the inverse for a matrix that represents an invertible mapping.
A-1 A I = To solve for a, b, c, reduce: To solve for d, e, f, reduce: To solve for g, h, j, reduce:
It is more efficient to do the three problems below in one step To solve for a, b, c, reduce: To solve for d, e, f, reduce: To solve for g, h, j, reduce:
-1 It is more efficient to do the three problems below in one step
-1 It is more efficient to do the three problems below in one step 1 1 0 - 1
-2 It is more efficient to do the three problems below in one step 0 1 -2 3
-4 It is more efficient to do the three problems below in one step 0 7 -4
-1 It is more efficient to do the three problems below in one step 3 -8 4 0
A I reduces to: I A-1