21-241: Online Assignment #13

There was an error in the way Problem #5 was being graded on this week's assignment. I'm pretty sure I figured out the problem and fixed it. If it was giving you problems, give it another try.

21-241: Week #1

The assignemnts for Week #1 have been posted on the Schedule page. Note that you will have to click through some links to get to the homework problems that are due on Friday.

The textbook introduces the idea of a matrix slightly earlier than we will in class - only a day or two, but it makes a difference due to the timing of HW#1. The homework problems selected will not require you to think in terms of matrices. We'll save that for next week.

21-260: Edits to Online Assignment #2

I need to make some comments and clarifications about this week's online assignment.

1. First, you need to find a differential equation, but you do not need to solve it! Also, I give you information that leads to an initial condition. You should enter an initial value problem (i.e. a differential equation with an initial condition) as your answer. I've updated the question to reflect this.
2. When I wrote this problem, I made a mistake that has caused the interest rates to be very small. That's okay, though. We can live with that. Also, I accidentally wrote "mayment" instead of "payment." Finally, the numerical value of k that you enter should be in units of [$ per year]. Your answer should be to the nearest dollar. Blackboard won't let me make these corrections/updates in the problem, though.
3. This is a linear differential equation, which we will discuss in class tomorrow. If you work out the answer to 2 decimal places, you should be okay.
4. Same as for problem 3.

21-260: Edits to Online Assignment #1

I've made a couple corrections to the problems on Wednesday's online assignment. I know some of you (75 according to Blackboard) have already attempted these problems, but I don't think should create too many problems. Here are the changes I've made:

1. In problem #4, I've changed "dy/dx" to "dy/dt", since the variable on the right hand side of the equations is t, not x.
2. In problem #5, I've changed "f(t)" to "f(x)", since the independent variable in the differential equations is x.

21-270: Week #15

The reading and homework for Week #15 have been posted. You can follow the link from the Schedule page.

21-241: Week #15

The reading and homework assignments for Week #15 have been posted. You can follow the link from the Schedule page.

21-241: Week #14

The reading and homework assignments for Week #14 have been posted. You can follow the link from the Schedule page.

21-270: Week #14

The reading and homework assignments for Week #14 have been posted. You can follow the link from the Schedule page.

21-241: Homework #12 typo

There is a misprint in one of the problems in the electronic version of the text. In the electronic version, problem 5.3.22 makes reference to the matrix "[.4 .2.6 .8]". This should be a 2x2 matrix with [.4 .2] in the first row, and [.6 .8] in the second row.

21-241: Week #12

The reading and homework assignments for Week #12 have been posted. You can follow the link from the Schedule page.

21-270: Week #11

The reading and homework assignments for Week #1 have been posted. YOu can follow the link from the Schedule page.

21-241: Week #11

The reading and homework assignments for Week #1 have been posted. YOu can follow the link from the Schedule page.

21-270: Week #10

The reading and homework assignments for Week #10 have been posted. You can follow the link from the Schedule page.

21-241: Week #10

The reading and homework assignments for Week #10 have been posted. You can follow the link from the Schedule page.

21-270: Week #3

The reading and homework assignments for Week #3 have been posted. You can follow the link from the Schedule page.

21-241: Week #3

The reading and homework assignments for Week #3 have been posted. You can follow the link from the Schedule page.

21-241: Week #2

The reading and homework assignments for Week #2 have been posted. You can follow the link from the Schedule page. There is a written assignment due Wednesday. I will hold office hours on Tuesday from 5:00-6:30. I will announce my permanent office hours in class on Wednesday.

21-260: Week #15

The reading and homework assignments for Week #15 have been posted. You can follow the link from the Schedule page.

21-260: Week #14

The reading and homework assignments for Week #14 have been posted. You can follow the link from the Schedule page.

21-260: Week #12

The reading and homework assignments for Week #12 have been posted. You can follow the link from the Sceudule page.