Resources

Examinations

Midterm 1

Midterm 2

Midterm 3

Midterm 3

Quizzes

Quiz 1 - August 29

The quiz will ask you to find the row reduced echelon form of a matrix.

Quiz 2 - September 5

The quiz will ask you to find the row reduced echelon form of a matrix.

Quiz 3 - September 19

The quiz will ask you to find the parametric vector form for the solutions to a vector equation.

Quiz 4 - September 26

The quiz will ask you to compute some matrix products.

Quiz 5 - October 3

The quiz will ask you to compute the inverse of a matrix.

Quiz 6 - October 24

The quiz will ask you to compute a basis for the null space of a matrix.

Quiz 7 - October 31

The quiz will ask you to compute a basis for the column space of a matrix.

Quiz 8 - November 7

The quiz will ask you to compute a change-of-basis matrix.

Quiz 9 - November 21

The quiz will ask you to find eigenspaces of a matrix.

Assignments

Assignment 1 - Due August 29

Do the following problems from the text.

Section Problems
1.1 11-14, 20, 39-42
1.2 1, 7, 11, 21, 45
1.3 5, 13, 18, 34

Assignment 2 - Due September 5

Do the following problems from the text.

Section Problems
1.4 12, 21-22
1.5 5, 6, 11, 12, 23

The following problems require formal proofs.

Problem A: Let \(a,b\) be real numbers and let \(\mathbf{u},\mathbf{v}\) be column vectors in \(\mathbb{R}^n\). Prove that \((a+b)(\mathbf{u}+\mathbf{v}) = a\mathbf{u}+b\mathbf{u}+a\mathbf{v}+b\mathbf{v}\).

Problem B: Let \(X\) and \(Y\) be finite subsets of \(\mathbb{R}^n\). Prove that \(\operatorname{Span}(X \cap Y) \subseteq \operatorname{Span}(X) \cap \operatorname{Span}(Y)\).

Assignment 3 - Due September 19

Do the following problems from the text.

Section Problems
1.7 1, 7, 11
1.8 4, 17
1.9 16, 22, 37, 38

The following problems require formal proofs.

Problem A: Let \(m\) and \(b\) be real numbers. Let \(f : \mathbb{R}^1 \to \mathbb{R}^1\) be the function given by \(f(x)=mx+b\). Prove that \(f\) is a linear transformation if and only if \(b=0\).

Problem B: Let \(X,Y,Z\) be sets and let \(f : X \to Y\) and \(g : Y \to Z\) be functions. Prove that if \(g \circ f\) is injective, then \(f\) is injective.

Assignment 4 - Due September 26

Do the following problems from the text.

Section Problems
2.1 2, 9, 10, 12
2.2 9, 39, 40, 41, 42

The following problems require formal proofs.

Problem A: Let \(A\) be an \(m \times n\) matrix and \(B\) be an \(n \times p\) matrix. Prove that \((AB)^T=B^TA^T\).

Problem B: Prove that the matrix \(A = \begin{pmatrix} a & b\\ c & d \end{pmatrix}\) is invertible if and only if \(ad-bc \ne 0\).

Assignment 5 - Due October 3

Do the following problems from the text.

Section Problems
2.3 1, 2, 3, 4, 5, 6
3.1 2, 4, 10, 14

The following problems require proofs.

Problem A: Let \(X\) and \(Y\) be nonempty sets. Let \(f : X \to Y\) be an injective function. Prove that there exists a function \(g : Y \to X\) such that \(g \circ f\) is the identity on \(X\). Give an explicit example to show that \(g\) is not necessarily unique.

Problem B: Let \(X\) and \(Y\) be nonempty sets. Let \(f : X \to Y\) be a surjective function. Prove that there exists a function \(h : Y \to X\) such that \(f \circ h\) is the identity on \(Y\). Give an explicit example to show that \(h\) is not necessarily unique.

Assignment 6 - Due October 24

Do the following problems from the text.

Section Problems
3.2 6, 8, 12, 14, 46
4.1 10, 12, 16, 18

The following problems require formal proofs.

Problem A: A matrix \(A\) is symmetric if \(A=A^T\). Prove that the set of symmetric matrices form a subspace of the vector space of all \(n \times n\) matrices.

Problem B: Let \(U,V\) be subspaces of a vector space \(W\). Prove that \(U \cap V\) is a subspace of \(W\). Find an example where \(U \cup V\) is not a subspace of \(W\).

Assignment 7 - Due October 31

Do the following problems from the text.

Section Problems
4.2 2, 6, 24
4.3 2, 4, 8, 14, 16

The following problems require formal proofs.

Problem A: Let \(T : V \to W\) be a linear transformation from a vector space \(V\) to a vector space \(W\). Prove that the range of \(T\) is a subspace of \(W\).

Problem B: Let \(T : V \to W\) be a linear transformation from a vector space \(V\) to a vector space \(W\). Suppose \(v_1,\ldots, v_p\) is a linearly independent set in \(V\). Prove that, if \(T\) is injective, then \(T(v_1),\ldots, T(v_p)\) is linearly independent.

Problem C: Let \(T : V \to W\) be a linear transformation from a vector space \(V\) to a vector space \(W\). Suppose \(v_1,\ldots, v_p\) spans \(V\). Prove that, if \(T\) is surjective, then \(T(v_1),\ldots, T(v_p)\) spans \(W\).

Assignment 8 - Due November 7

Do the following problems from the text.

Section Problems
4.4 4, 8, 14, 32, 36
4.5 2, 4, 8

The following problems require formal proofs.

Problem A: Let \(T : V \to W\) be an invertible linear transformation from a vector space \(V\) to a vector space \(W\). Prove that if \(v_1,\ldots, v_p\) is a basis for \(V\), then \(T(v_1),\ldots, T(v_p)\) is a basis for \(W\).

Problem B: Let \(\mathcal{B}\) be a finite basis for a vector space \(V\). Prove that the vectors \(u_1,\ldots, u_p\) in \(V\) are linearly independent if and only if the coordinate vectors \([u_1]_{\mathcal{B}}, \ldots, [u_p]_{\mathcal{B}}\) are linearly independent.

Problem C: Let \(U,V,W\) be vector spaces and let \(T: U \to V\) and \(S: V \to W\) be linear transformations. Prove that if \(\operatorname{im}(T) \cap \operatorname{ker}(S) = \{0\}\) then \(\operatorname{ker}(T) = \operatorname{ker}(S \circ T)\).

Assignment 9 - Due November 21

Do the following problems from the text.

Section Problems
4.6 2, 6, 8, 16
5.4 2, 6, 8,
5.1 2, 4, 10, 14

The following problems require formal proofs.

Problem A: Let \(A\) and \(B\) be \(n \times n\) matrices. Prove that if \(A\) is similar to \(B\) and \(A\) is invertible, then \(B\) is invertible and \(A^{-1}\) is similar to \(B^{-1}\).

Problem B: Let \(M_n\) be the set of \(n \times n\) matrices. Define a relation \(\sim\) on \(M_n\) where \(A \sim B\) means \(A\) is similar to \(B\). Prove that \(\sim\) is an equivalence relation.