Math 2280-002
Spring 2020
Lectures

2280-2 home page
Professor Korevaar's home page
Department of Mathematics
College of Science
University of Utah

I will bring hard copies of lecture note outlines to class and post the filled-in versions after class. Notes should always be posted by 5:00 p.m. the day before class so that you may preview them if desired.

Week 1: January 6-10 Sections 1.1-1.4
      jan6.pdf 1.1 introduction to differential equations and Chapter 1.     jan6post.pdf   after-class version.
      jan7.pdf 1.2, 1.4 separable differential equations     jan7post.pdf   after-class version.
      jan8.pdf 1.3-1.4 slope fields; existence and uniqueness theorem for first order DE IVPs.     jan8post.pdf   after-class version.
      jan10.pdf 1.3-1.4 continued; IVP examples and the existence-uniqueness theorem.     jan10post.pdf   after-class version.

Week 2: January 13-17 Sections 1.4-1.5, 2.1-2.2
      jan13.pdf 1.5 introduction to first order linear differential equations     jan13post.pdf   after-class version.
      jan14.pdf 1.3-1.4 further examples; mathematical modeling and experiment for Toricelli's Law.     jan14post.pdf   after-class version.
      jan15.pdf 1.5 input-output applications for linear differential equations.     jan15post.pdf   after-class version.
      jan17.pdf 2.1 improved population models     jan17post.pdf   after-class version.

Week 3: January 21-24 Sections 2.1-2.3
      jan21.pdf 2.1-2.2 population modeling and phase diagram analysis     jan21post.pdf   after-class version.
      jan22.pdf 2.2 phase diagram analysis continued, fisheries example.     jan22post.pdf   after-class version.
      jan24.pdf 2.3 improved velocity models.     jan24post.pdf   after-class version.

Week 4: January 27-31 Sections 2.3-2.6, 3.1
      jan27.pdf 2.3-2.4 improved velocity models, introduction to Euler's method for first order IVPs.     jan27post.pdf   after-class version.
      jan28.pdf 2.5-2.6 improved Euler and Runge-Kutta numerical methods.     jan28post.pdf   after-class version.
      jan29.pdf matlab scripts for numerical computations related to IVPs.     jan29post.pdf   after-class version.
      jan31.pdf 3.1 introduction to higher order differential equations     jan31post.pdf   after-class version.

Week 5: February 3-7 Sections 3.1-3.3
      Monday February 3 was a snow day.
      feb4.pdf 3.1-3.2 higher order linear differential equations     feb4post.pdf   after-class version.
      feb5.pdf 3.2-3.3 higher order linear differential equations     feb5post.pdf   after-class version.
      feb7.pdf 3.3 solution space algorithm for constant coefficient linear DE's.     feb7post.pdf   after-class version.

Week 6: February 10-14 Sections 3.3-3.4; exam 1
      feb10.pdf 3.3-3.4     feb10post.pdf   after-class version.
      feb11.pdf 3.3-3.4 continued     feb11post.pdf   after-class version.
      feb12.pdf 3.4 and exam review.     feb12post.pdf   after-class version.

Week 7: February 18-21 Sections 3.5-3.6
      feb18.pdf 3.5 finding particular solutions to nonhomogeneous constant-coefficient linear DE's.     feb18post.pdf   after-class version.
      feb19.pdf 3.5 completed     feb19post.pdf   after-class version.
      feb21.pdf 3.5-3.6 case 2 in 3.5, and begin 3.6 applications to forced oscillations in mass-spring (and equivalent) configurations.     feb21post.pdf   after-class version.

Week 8: February 24-28 Sections 3.6-3.7, 4.1, 5.1-5.2
      feb24.pdf 3.6 forced oscillations completed.     feb24post.pdf   after-class version.
      feb25.pdf 3.6-3.7 and forced oscillations for RLC circuits     feb25post.pdf   after-class version.
      feb26.pdf 4.1 systems of first order differential equations     feb26post.pdf   after-class version.
      feb28.pdf 5.1 and intro to 5.2: differentiation rules for sums, products, multiples of matrix-valued functions; solving homogeneous first order linear systems of DE's using eigendata.     feb28post.pdf   after-class version.

Week 9: March 2-6 5.1-5.3
      mar2.pdf 5.1-5.2 linear systems of DE's and exponential solutions.     mar2post.pdf   after-class version.
      mar3.pdf 5.1-5.2 continued.     mar3post.pdf   after-class version.
      mar4.pdf 5.2-5.3 complex eigendata; shape of phase portraits for n=2 first order linear homogeneous DE systems.     mar4post.pdf   after-class version.
      mar6.pdf 5.3 phase portraits for real eigendata     mar6post.pdf   after-class version.

Week 10: March 18-20 5.3, 6.1, 6.3
      mar18.pdf 5.3 phase portraits, complex and real eigendata; intro to 6.1 nonlinear systems
        mar18post.pdf   after-class version.   YouTube:   complex eigendata   real eigendata   nonlinear systems
      mar20.pdf 6.2-6.3 linearization near equilibrium points
        mar20post.pdf   after-class version.   YouTube:   linearization

Week 11: March 23-27 6.3-6.4, midterm review.
      mar23.pdf 6.3 ecological models
        mar23post.pdf   after-class version.   YouTube:   interacting species
      mar24.pdf 6.4 mechanical models
        mar24post.pdf   after-class version.   YouTube:   mechanical models
      exam2review.pdf midterm review notes

Week 12: March 30 - April 3 6.5 (optional); 5.4, 5.6.
      mar30a.pdf 6.5: survey of higher dimensional phenomena (optional)
      mar30b.pdf 5.4 unforced undamped mass-spring systems
       YouTube:   fundamental modes and oscillations demo, for 2-mass 3-spring configuration.
        mar30bpost.pdf   after-class version    YouTube:   unforced mass spring systems
      mar31.pdf 5.4 forced undamped mass-spring systems
       YouTube:   shake table earthquake excitation of normal modes demo.
        mar31post.pdf   after-class version    YouTube:   forced mass spring systems
      apr1.pdf 5.6 matrix exponentials and homogeneous systems of differential equations
        apr1post.pdf   after-class version    YouTube:   matrix exponentials and DE's
      apr3a.pdf 5.7 matrix exponentials for inhomogeneous systems.
        apr3apost.pdf   after-class version    YouTube:   matrix exponentials as integrating factors
      apr3b.pdf 5.7 exp(tA) when A is not diagonalizable
        apr3bpost.pdf   after-class version    YouTube:   exp(tA) for non-diagonalizable A

Week 13: April 6-10 9.1-9.4
      apr6.pdf 9.1 intro to Fourier series
        apr6post.pdf   post notes.    YouTube:   Intro to Fourier series, as orthogonal projection.
      apr7.pdf 9.3 differentiating and integrating Fourier series
        apr7post.pdf   post notes.    YouTube:   differentiating and integrating Fourier series.
      apr8.pdf 9.2-9.3 Fourier series for 2L-periodic functions; even and odd extensions.
        apr8post.pdf   post notes.    YouTube:   2L-periodic Fourier series; cosine and sine series
      apr10.pdf 9.4 mass-spring systems with periodic forcing functions: resonance and practical resonance.
        apr10post.pdf   post notes.    YouTube:   Periodic forced oscillations via Fourier series

Week 14: April 13-17 9.5-9.6
      April 13 is a sag day - no new material.
      apr14.pdf 9.5 Introduction to the heat equation
        apr14post.pdf   post notes.    YouTube:   heat equation and product solutions, modeling and visualization
      apr15.pdf 9.5 Heat equation, worked examples.
        apr15post.pdf   post notes.    YouTube:   Fourier series to solve the heat equation
      apr17.pdf 9.6 Introduction to the wave equation.
        apr17post.pdf   post notes.    YouTube:   IBVPs for the wave equation, and product function solutions

Week 15: April 20-21 9.6, review notes.
      apr20.pdf 9.6 examples connecting Fourier series to traveling waves solutions.
        apr20post.pdf   post notes.    YouTube:   connecting traveling wave and Fourier series solutions