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says
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Mod note: Moved from Precalc section
1. Homework Statement
Given l : IR3 → IR3 , l(x1, x2, x3) = (x1 + 2x2 + 3x3, 4x1 + 5x2 + 6x3, x1 + x2 + x3), find Ker(l), Im(l), their bases and dimensions.
My language in explaining my steps is a little sloppy, but I'm trying to understand the process and put it in terms that I understand.
ker(l) Ax=0
Step 1: Find the matrix associated to this transformation using the standard basis.
l(1,0,0) = (1,4,1)
l(0,1,0) = (2,5,1)
l(0,0,1) = (3,6,1)
Im(l) =
[1] [4] [1]
[2] , [5] , [1]
[3] [6] [1]
To find Ker(l) = Ax=0. Put Im(l) into an augmented matrix and set it =0
[1 4 1 |0]
[2 5 1 |0]
[3 6 1 |0]
Reduced row echelon form =
[1 0 -1/3 |0]
[0 1 1/3 |0]
[0 0 0 |0]
X1= X1 [1] X2 [0] X3 [ -1/3]
X2= X1 [0] + X2 [1] + X3 [ 1/3 ]
X3= X1 [0] X2 [0] X3 [ 0 ]
ker(l) =
[1] [0] [-1/3]
[0] , [1] , [1/3]
[0] [0] [0]
Basis(l) = minimum number of vectors that span the subspace
[1] [0]
[0] , [1]
[0] [0]
Dimension = number of vectors that span the subspace = 2
I hope I've done this right.
1. Homework Statement
Given l : IR3 → IR3 , l(x1, x2, x3) = (x1 + 2x2 + 3x3, 4x1 + 5x2 + 6x3, x1 + x2 + x3), find Ker(l), Im(l), their bases and dimensions.
My language in explaining my steps is a little sloppy, but I'm trying to understand the process and put it in terms that I understand.
Homework Equations
ker(l) Ax=0
The Attempt at a Solution
Step 1: Find the matrix associated to this transformation using the standard basis.
l(1,0,0) = (1,4,1)
l(0,1,0) = (2,5,1)
l(0,0,1) = (3,6,1)
Im(l) =
[1] [4] [1]
[2] , [5] , [1]
[3] [6] [1]
To find Ker(l) = Ax=0. Put Im(l) into an augmented matrix and set it =0
[1 4 1 |0]
[2 5 1 |0]
[3 6 1 |0]
Reduced row echelon form =
[1 0 -1/3 |0]
[0 1 1/3 |0]
[0 0 0 |0]
X1= X1 [1] X2 [0] X3 [ -1/3]
X2= X1 [0] + X2 [1] + X3 [ 1/3 ]
X3= X1 [0] X2 [0] X3 [ 0 ]
ker(l) =
[1] [0] [-1/3]
[0] , [1] , [1/3]
[0] [0] [0]
Basis(l) = minimum number of vectors that span the subspace
[1] [0]
[0] , [1]
[0] [0]
Dimension = number of vectors that span the subspace = 2
I hope I've done this right.
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