Questions
Question 1
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State the definition of a linearly independent list \(\mathbf v_1,\ldots,\mathbf v_k\).
Question 2
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What does it mean for a list of vectors to be linearly dependent?
Question 3
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Explain why any list containing \(\mathbf0\) is linearly dependent.
Question 4
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Are \((1,0)\) and \((0,1)\) linearly independent in \(\mathbb R^2\)?
Question 5
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Test whether \((1,2)\) and \((3,6)\) are linearly independent.
Question 6
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Test whether \((2,1)\) and \((1,-1)\) are linearly independent.
Question 7
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Explain why three vectors in \(\mathbb R^2\) must be linearly dependent.
Question 8
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Test whether \((1,0,0),(0,1,0),(1,1,0)\) are linearly independent.
Question 9
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Test whether \((1,0,1),(0,1,1),(1,1,0)\) are linearly independent.
Question 10
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Test whether the polynomials \(1+x\), \(1-x\), and \(2\) are linearly independent in \(P_1\).
Question 11
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Use a determinant to test whether \((1,2)\) and \((3,5)\) are independent in \(\mathbb R^2\).
Question 12
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A pair of non-zero displacement directions in a plane are not scalar multiples. Explain why they are independent.
Question 13
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Find all \(k\) for which \((1,k)\) and \((2,4)\) are linearly dependent.
Question 14
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Find all \(a\) for which \((1,0,a),(0,1,a),(1,1,2a)\) are linearly independent.
Question 15
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For which \(t\) are \((1,0,1),(0,1,1),(1,1,t)\) linearly independent?
Question 16
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For which \(a\) are \((1,a)\) and \((a,1)\) linearly dependent?
Question 17
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For which \(p\) are the polynomials \(1+x\), \(1+px\) independent in \(P_1\)?
Question 18
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A student checks that no two vectors in a list of three are scalar multiples and concludes the list is independent. Give a counterexample.
Question 19
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Prove that any subset of a linearly independent list is linearly independent.
Question 20
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Prove that if one vector in a finite list is a linear combination of the others, then the list is linearly dependent.