Differential Equations
Math 2250-4
Spring 2012
Lecture Page

2250-4 home page
Department of Mathematics
College of Science
University of Utah

Lecture notes will be posted by 4:00 p.m. the day before class. I strongly recommend bringing a copy of these notes to class, so we can go through the concepts and fill in the details together.

Week 1: January 9-13
    jan9.pdf   jan9.mw  Introduction to course and Chapter 1.
    jan10.pdf   jan10.mw  1.2: differential equations of the form y'(x)=f(x).
    jan11.pdf   jan11.mw  1.2-1.3: slope fields and graphs of solutions to first order differential equations.
    jan13.pdf   jan11.mw  1.3-1.4: slope fields and the existence uniqueness theorem for IVP solutions, illustrated with separable differential equations.

Week 2: January 17-20
    jan17.pdf   jan17.mw  1.4-1.5; Toricelli experiment
    jan18.pdf   jan18.mw  1.5: first order linear differential equations
    jan20.pdf   jan20.mw  1.5 continued, and EP3.7 electrical circuits.

Week 3: January 23-27
    jan23.pdf   jan23.mw  2.1: improved population models
    jan24.pdf   jan24.mw  2.2: autonomous differential equations
    jan25.pdf   jan25.mw  2.2-2.3: applications of autonomous differential equations
    jan27.pdf   jan27.mw  2.3: improved velocity-acceleration models.

Week 4: January 30 - February 3
    jan30.pdf  jan30.mw  2.3: escape velocity
    jan31.pdf  jan31.mw  2.4-2.6: numerical methods for 1st order initial value problems.
      numericaltemplate.pdf  algorithms for Euler, improved Euler, and Runge Kutta.
    feb1.pdf  feb1.mw  3.1-3.2 linear systems of algebraic equations
    feb3.pdf  feb3.mw  3.1-3.3 Gaussian elimination and reduced row echelon form for finding the solution sets to linear systems of equations.

Week 5: February 6 - 10
    feb6.pdf  feb6.mw  3.3: deducing possible solution set structure from reduced row echelon form of the augmented and unaugmented matrices.
    feb7.pdf  feb7.mw  3.3-3.4 implications and applications using reduced row echelon form; matrix times vector algebra and consequences.
    feb8.pdf  feb8.mw  3.4-3.5 matrix algebra and introduction to matrix inverses.
    feb10.pdf  feb10.mw  3.5 matrix inverses.

Week 6: February 13 - 17
    feb13.pdf  feb13.mw  3.6:determinants
    feb14.pdf  feb14.mw  3.6:determinants and the adjoint formula for matrix inverses; Cramer's rule.
    exam1review.pdf  exam1review.mw  for February 15.
    feb17.pdf  feb17.mw  4.1-4.3 introduction to concepts related to linear combinations of vectors and functions.

Week 7: February 21 - 24
    feb21.pdf  feb21.mw  4.1-4.3: linear combinations, span and independence.
    feb22.pdf  feb22.mw  4.1-4.4: vector spaces and subspaces.
    feb24.pdf  feb24.mw  4.4: bases and dimension.

Week 8: February 27 - March 2
    feb27.pdf  feb27.mw  Key concepts and examples from 4.1-4.4
    feb28.pdf  feb28.mw  5.1 second order linear differential equations and connections to vector space concepts.
    feb29.pdf  feb29.mw  5.1-5.2 nth-order linear differential equations and connections to vector space concepts.
    mar2.pdf  mar2.mw  5.2-5.3 expanded discussion of linear independence for functions (5.2), and how to find the solution space for constant coefficient nth order linear homogeneous DEs (5.3).

Week 9: March 5 - 9
    mar5.pdf  mar5.mw  5.3 The solution space for constant coefficient nth order linear homogeneous DEs, when the characteristic polynomial has repeated and/or complex roots.
    mar6.pdf  mar6.mw  5.4 unforced mechanical oscillations.
    mar7.pdf  mar7.mw  5.4 unforced mechanical oscillations: pendulum model; mass-spring and pendulum experiments vs. predictions.
    mar9.pdf  mar9.mw  5.5 particular solutions to non-homogeneous linear differential equations

Week 10: March 19 - 23
    mar19.pdf  mar19.mw  5.5-5.6: variation of parameters for particular solutions. Applications of non-homogeneous differential equation theory to forced mechanical problems: undamped forced oscillations.
    mar20.pdf  mar20.mw  5.5-5.6, EP3.7 continued. damped forced oscillations and practical resonance in mechanical problems and in electrical circuits.
    mar21.pdf  mar21.mw  5.6, EP3.7 continued: using conservation of energy to find natural frequencies in single and multi-component systems.
    mar23.pdf  mar23.mw  10.1-10.2 Laplace transforms, and what they have to do with Chapter 5.

Week 11: March 26 - 30
    mar26.pdf  mar26.mw  10.1-10.3 Laplace transforms, and using them to re-solve the initial value problems for mechanical oscillations.
    mar27.pdf  mar27.mw  10.2-10.3 continued.
    exam2review.pdf  exam2review.mw  Review of key ideas from 4.1-4.4, 5, EP3.7, 10.1-10.4, for the Thursday exam. Try to fill in details before class!
       exam2reviewfilledin.pdf  exam2reviewfilledin.mw  cleaned up versions of how we filled in these notes during class.
    mar30.pdf  mar30.mw  10.4-10.5,EP7.6: further applications of Laplace transforms to differential equations.

Week 12: April 2 - 6
    apr2.pdf  apr2.mw  10.5, EP7.6 Laplace transforms for periodic function forcing, impulse function forcing, and why the convolution table entry is important in applications.
    apr3.pdf  apr3.mw  6.1-6.2: eigenvalues and eigenvectors for square matrices.
    apr4.pdf  apr4.mw  6.2: eigenspace bases and matrix diagonalizability.
    apr6.pdf  apr6.mw  7.1 systems of differential equations.

Week 13: April 9 - 13
    apr9.pdf  apr9.mw  7.1-7.3 systems of differential equations, theory and computations
    apr10.pdf  apr10.mw  7.3 The eigenvector method for solving homogeneous first order systems of differential equations. What to do about complex eigenvalues?
    apr11.pdf  apr11.mw  7.3 Solutions to non-homogeneous linear systems, as illustrated with a tank cascade.
    apr13.pdf  apr13.mw  7.4 undamped multi-component mechanical systems

Week 14: April 16 - 20
    apr16.pdf  apr16.mw  7.4 unforced and forced mechanical systems with several components
    apr17.pdf  apr17.mw  7.4 transverse oscillations and earthquakes shaking buildings. Also, introduction to Chapter 9.
    apr18.pdf  apr18.mw  9.1-9.2 autonomous systems of first order differential equations: phase portraits, equilibrium solutions, and linearization near equilibria.
    apr20.pdf  apr20.mw  9.2-9.3 classifying equilibrium solutions to autonomous systems of DEs, based on linearization. Applications to interacting populations.

Week 15: April 23 - 25
    apr23.pdf  apr23.mw  9.2-9.4 classification of equilibrium points, continued. Application to phase diagrams for nonlinear mechanical systems.
    apr24.pdf  apr24.mw  9.4 Phase portraits and stability analysis for first order systems arising from autonomous forced oscillation problems.
    Math2250review.pdf  Course review notes for Wednesday