# MIT OpenCourseWare Linear Algebra

1. Dec 13, 2007

### kocher

2. Dec 13, 2007

### topherfox

omg, I didn't know about this website... you have just made my life, seriously, I am going to learn the sh*t out of everything

Great idea!

3. Dec 13, 2007

### kocher

Try to learn that linear alg class this weekend then let me know how it was lol

4. Dec 13, 2007

### cgw

I'm actually going through it right now. I'm spending about an hour a day which is all I can spare but also about all I can take.
How long is your winter break.
As far as the material goes, I have never had exposure to LA before so it is very good for me. It seems pretty straight forward to me so either it is and/or the course (lectures and book) make it seem so.

5. Dec 13, 2007

### kocher

My break begins tomorrow after my 10:30 physics final :) I have 12/14 to 1/14 off from class, if it runs into next semester by a week or two it won't be too bad.

I haven't been too exposed to LA. I bought the book, hopefully I can learn it before i take my math phys class next semester

6. Dec 14, 2007

### cgw

Let us know how it works out.

7. Jan 3, 2008

### Ghostrider

I watched the linear algebra lectures over my winter break. I watched 2/3rds of the lectures, but did not attempt any of the book problems because I don't have the book. It was definitely helpful as a refresher. It's a great resource, I want to see more schools open up their courses for the curious.

8. Jan 4, 2008

### topherfox

yeah I ended up doing the Physics one instead :P

9. Jan 13, 2008

### mathwonk

i am afraid just watching lectures and not doing problems is of minimal value. at leaST I RECALL as a grad student sitting through lectures in algebraic topology about 7 times, but never really getting it until i started working problems, giving the lectures myself, and writing things out.

10. Jan 15, 2008

### Rockin' Roel

This guy nailed the SVD. It seemed so complicated when my Belgian professor explained it to me. The only problem is: in that lecture about the SVD, he makes a mistake. When trying to come up with the SVD of:
$$A=\begin{bmatrix} 4 & 4 \\ -3 & 3 \end{bmatrix}$$
He gets:
$$A=\begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix} \begin{bmatrix} \sqrt{32} & 0 \\ 0 & \sqrt{18} \end{bmatrix} \begin{bmatrix} \frac{1}{\sqrt{2}} & \frac{1}{\sqrt{2}} \\ \frac{1}{\sqrt{2}} & \frac{-1}{\sqrt{2}} \end{bmatrix}$$
I figured out by toying around that it should be:
$$A=\begin{bmatrix} 1 & 0 \\ 0 & 1 \end{bmatrix} \begin{bmatrix} \sqrt{32} & 0 \\ 0 & \sqrt{18} \end{bmatrix} \begin{bmatrix} \frac{1}{\sqrt{2}} & \frac{1}{\sqrt{2}} \\ \frac{-1}{\sqrt{2}} & \frac{1}{\sqrt{2}} \end{bmatrix}$$
But why? I don't see where he (and I) made that mistake. I don't find a correction of it in his other lectures either. Can anyone explain this to me?

11. Jan 15, 2008

### d_leet

He made a mistake, people make mistakes all the time it isn't really a big deal. And can you imagine how much time would be wasted if every lecturer devoted a bit of time to correct every error that had been made in a previous lecture, that would be just stupid there is no reason to expect someone to do that.

12. Jan 15, 2008

### Rockin' Roel

It just bothers me, I'm sure I'll understand once I'm ready for my exam. Mistakes always bother you, and in real life situations, in real problems, who knows what could happen? I'm just fooling around...

13. Jan 18, 2008

### cgw

I hear you. I got halfway through the lectures before I decided to buy the book and start over.

14. Feb 2, 2008

### Shing

I am self-studying the MIT Linear Algebra now!!
We should share what we learn here later !! ^^

15. Feb 4, 2008

### cgw

I am finding it like trying to learn spanish. I completely "get it" but forget all the little rules 5 minutes after I hear them.
I am trying to work through the exercises that have answers in the book. I am in chapter 6 now and the going got a little slower when I hit this chapter.