Homeworks
- Suggested problems (updated 11/21): pdf
- #1 has been solved
- new question added
- note the increased value of the remaining unsolved questions
- #2 has been solved
- #3 has been solved
- Homework 3: assignment and solutions
- Quiz 3: quiz and solutions
- For
#1, if you obtained the roots -1, -e^{i*2*pi/3}, -e^{i*4*pi/3}, please
either bring me your quiz or email me a picture of the question
- Homework 5: assignment and solutions
- Quiz 5: quiz and solutions
- For #10 in Section 4.1, the answer in the back of the book is missing a factor of e^{-s} on the first s in the numerator
- Sorry...the answer in the book is right. My fault. Won't be on the quiz...
- Homework 6: assignment and solutions
- Quiz 6: quiz and solutions
- For the Section 5.4 problems, please draw the phase portraits by hand instead of using a computer
- I will discuss the phase portrait for Section 5.4 #8 in class
- For #21b) in Section 4.6, the answer in the back of the book should have a sin(10t), not sin(t)
Additional material
- Responses to anonymous feedback (updated 11/21): pdf
- Existence and uniqueness proof: pdf
- Rescaling examples from class: pdf
- Midterm 1 from 2013: midterm and solutions
- our midterm will cover everything up to and including forced oscillations (essentially everything before Laplace transforms)
- Inverse Laplace transforms, and the relationship between Fourier and Laplace transforms: pdf
- Final practice questions: pdf
- final exam is at 8:30 AM on Dec. 4 in Dalplex
- Laplace transform table: pdf
- this is what you will have on the final
- Midterm 2 from 2013: midterm and solutions
- the left-hand side of #3 should read y'' + 6y' + 13y = ...
Addendum to lecture notes
- September 16: the \theta term on page T9 should be replaced by -\theta.
- September 23: the
v + xdv/dx term in first order homogeneous equations comes from
computing d(xv)/dx after the substitution v = y/x (see page H2).
- October 2: the
third order example on page D36 should read y''' - 3y'' - 4y' + 12y =
0. It is correct in the pdf, but please correct this in your notes.
- October 2: the
signs flipped on the right-hand side of the second line of page D44
because of the negative sign on the second to last line of page D43.
- October 7: at the bottom of pag D47, the very last terms should read "-(x-1) e^{-x} + \int e^{-x} dx"
- October 7: first line at the top of page D48 should read "-(x-1) e^{-x} - e^{-x} + c"
- October 16: the (2,1) entry of the determinant in the denominator on page V4 should be y_1^\prime
- November 6: please note the correction made at the bottom of page P68
Lectures