Math 2135
Linear Algebra


Spring 2020

Please see below for lecture summaries, homework and other study material. For your grades, please visit our Canvas website.

Date Topics
Jan.13. Matrix encodings of linear systems. Elementary row operations on matrices.
Jan.15. Echelon and reduced echelon forms. Examples of row reduction to echelon forms.
HW1 (due Wed. Jan. 22.): 1.1: 4, 10, 12, 20, 24; 1.2: 2, 8, 10, 16, 18, 22, 26.
Jan.17. The row reduction algorithm. Pivots. Existence and uniqueness of solutions to linear systems.
Jan.20. Martin Luther King Holiday; no class.
Jan.22. Linear combinations of vectors. Spans.
HW1 (due Fri. Jan. 31.): 1.2: 20, 24, 28; 1.3: 8, 10, 12, 18, 22, 33; 1.4: 10, 15, 18, 26.
Jan.24. Matrix-vector product. Vector equations and matrix equaitons.
Jan.27. Two existence theorems on solutions of matrix equations.
Jan.29. Homogeneous matrix equations. Solutions of homogeneous vs non-homogeneous equations.
HW3 (due Wed. Feb.5): 1.4: 25, 27, 36; 1.5: 4, 16, 24, 26, 28, 36; 1.7: 6, 12, 20, 32.
Jan.31. Linear independence.
Feb.03. More on linear independence.
Feb.05. Definition of linear transformations. Connections to matrix multiplicaitons.
HW4 (due Wed. Feb.12): 1.7: 36, 37, 38; 1.8: 6, 15, 16, 24, 32, 36; 1.9: 6, 8, 14, 22.
Feb.07. Consequences of linearity. The matrix of a linear map.
Feb.10 Geometric linear transformations in R^2.
Feb.12. Image and surjectivity; kernel and injectivity.
HW 5 (due Wed. Feb.19): 1.9: 2, 14, 26, 28, 36; 2.1: 2, 9, 10, 16, 20, 22, 24.
Feb.14. Scaling, addition and transposition of matrices. Properties of these operations.
Feb.17. Matrix multiplication and its properties.
Feb.19. More properties of matrix multiplication.
HW6 (due Wed. Feb.26): 2.1: 27, 28, 30; 2.2: 4, 6, 14, 16, 18, 22, 30, 32.
Feb.21. Invertible matrices: definition, properties, and relation to linear maps. Review for Midterm 1
Feb.24. Characterization of invertible matrices. Finding matrix inverses.
Feb.26. Review for Midterm 1.
HW7 (due Wed. Mar.4): 2.3: 6, 8, 13, 16, 18, 34.
Feb.28. Midterm 1 (Solutions)
Mar.02. Subspaces of vector spaces: definition and examples.
Mar.04. Subspaces arising from matrices and maps. Bases.
HW8 (due Wed. Mar.11.): 2.8: 1, 4, 7, 16, 18, 22, 24, 26, 28, 30.
Mar.06. Bases of R^n. Bases of null spaces and column spaces.
Mar.09. Bases verification and computation.
Mar.11. More bases computation. The rank-nullity theorem.
HW9 (due Fri. Mar.20.): 2.9: 10, 14, 15, 16, 20, 22, 23, 26; 3.1: 2, 4, 12, 14.
Mar.13. Class format after transition to remote teaching. Determinants of matrices of small size.
Mar.16. Cofactor expansions.
Mar.18. Determimants, row operations and invertibility.
HW10 (due Mon. Mar.30.): 3.2: 18, 20, 22, 24, 28, 29, 38, 40. 3.3: 20, 22, 28.
Mar.20. Determinants of matrix products and transposes. Geometry of determinants.
Mar.30. Definition of abtract vector spaces. Spans, linear independence, subspace, and linear transformations, revisited.
Apr.01. Images and kernels. Bases and dimensions.
HW11 (due Fri.Apr.10.): 4.1: 6, 8, 10, 12, 20, 22, 28; 4.2: 10, 12, 18; 4.3. 14, 20; 4.5: 4, 8, 14.
Apr.03. Coordinate vectors. Coordinate mappings. Properties of linear isomorphisms.
Apr.06. Row space. Rank. Homework guide.
Apr.08. Change of basis.
HW12 (due Wed. Apr.15.): 4.4: 4, 6, 14, 17, 23, 28, 34; 4.7: 2, 4, 6, 8, 14, 15.
Apr.10. Finding change-of-basis matrices. Review for Midterm 2.
Apr.13. Matrix encodings of linear maps.
Apr.15. Midterm 2 (Solutions)
HW13 (due Fri. Apr.24.): 5.1: 2, 6, 10, 14, 18, 24; 5.2: 6, 12, 16; 5.4: 2, 4, 6.
Apr.17. Eigenvectors and eigenvalues.
Apr.20. Eigenspaces as null spaces. Finding eigenvalues via characteristic equations.
Apr.22. Complex eigenvalues. Algebraic vs. geometric multiplicities. Eigenbases.
HW14. (due Fri. May.1.): 5.2: 18; 5.3: 2, 6, 10, 12, 18, 24; 5.4: 12, 16, 17, 18.
Apr.24. Diagonalizability and diagonalization.
Apr.27. Inner products, lengths and distances.
Apr.29. Orthogonality. Orthogonal sets. Orthogonal projections.
HW15. (to be completed, but will not be collected): 6.1: 2, 6, 10, 14, 22, 24, 28; 6.2: 6, 7, 9, 12, 14.
May.06. Final Exam, 1:30 - 4:15 p.m. on Canvas.