I was an applied mathematics major in college, and had a fairly good grounding in statistics (including related topics such as probability theory and stochastic processes). At the time the major job opportunity associated with learning statistics was being an actuary; that didn’t sound too exciting to me, so I went off and did other things. I long ago forgot almost all of the mathematics I learned, due to not having to use it in my day-to-day work.

Now in the 21st century I come to find out that with the advent of big data

statistics is sexy. (If only I knew…) I’m not about to change careers, but I thought it might be fun (at least for my definition of fun) to refresh my skills in this area. I could take a statistics course, but I have no immediate need to run chi-square tests. (Though I am starting to learn how to use R.) My personal preference is for gaining an in-depth understanding of a subject, so I thought I’d instead start with relearning the underlying mathematics that I’d forgotten.

My chosen first task is therefore to relearn linear algebra, using as a textbook Gilbert Strang‘s out-of-print Linear Algebra and Its Applications, Third Edition, a copy of which I was able to pick up cheaply on Amazon. I’m a stickler for working through all the exercises in a textbook, and was initially doing it using pencil and paper. However after a while I got preoccupied by other things and stopped doing my math homework.

To rekindle my interest I hit upon the idea of publishing the worked-out exercises as blog posts, one per day. Besides giving me an incentive to keep working, this also allowed me to indulge another past interest in mathematics publishing using TeX and LaTeX. As a result of my previous job at the Mozilla Foundation I recently got re-interested in the general problem of displaying mathematics on the web. It’s a long-standing problem, and progress has come slowly.

There are some promising developments occurring in this area: The STIX Fonts project has released version 1.0 of a set of free high-quality mathematics fonts, the MathJax project has released version 1.0 of a new JavaScript library for supporting display of LaTeX content across multiple browsers (including generating MathML from LaTeX on the fly), and the enhancement of Firefox to support a new HTML5 parser will simplify incorporating MathML content into web pages.

In the future I may take advantage of some of these new technologies. However for now the path of least resistance is to take advantage of the LaTeX support provided by WordPress.com (where I’m hosting this blog.) Although it has its quirks it works reasonably well across browsers and it’s used by a lot of working mathematicians.

If you have any interest in the material I’m creating, please note that I’m making all of the content on this blog available under a Creative Commons license; see the sidebar for a link to the detailed license terms. If you do redistribute, reuse, or adapt the material please attribute it to me (Frank Hecker) and include a link to this blog (math.hecker.org). If you find typographical or mathematical errors in any of the exercise solutions please contact me at <frank@frankhecker.com>.

Finally, if you find these posts useful I encourage you to also check out the more current Linear Algebra and Its Applications, Fourth Edition, Dr Strang’s introductory textbook Introduction to Linear Algebra, Fourth Edition and the accompanying free online course, and Dr Strang’s other books.

Hi…Nice reading your blog. On somewhat parallel lines as yours, I did my grad. in computer science, and then through a circuitous route landed up as an business consultant. After several years in this line, I decided to re-learn mathematics too for the fun and satisfaction of it, and started with Strang’s linear algebra ðŸ™‚ Needless to say, I find your blog very helpful!.

After Strang I am aiming for Real Analysis by Chapman… let’s hope I get there…

Good luck of your math journey.. and do keep posting!

Regards – Sharad Bansal

Thanks for reading my blog and for stopping by to comment. I wish you luck in your own mathematics (re)education. Note that Strang’s book alone has over seven hundred exercises, so even if I can do one post a day (which is doubtful) it will take me over two years to get through the book. However on the plus side I will probably know linear algebra pretty well ðŸ™‚

Dear Hecker

You are the one and smart person in this world and i think who ever is doign our to “My math Homework” will love and get benifit of it……Please post some more notes like review exercises for chapter 2. Thanks

I applaud your righteous quest.

Please post the solutions of exercise 2.4 and above…. i find these posts very useful…. ðŸ™‚

Your post “My math homework ” was really helpful to me, especially exercise problems since I couldn’t get the solution for exercise problems. Thanks a lot ! I hope you post some more exercise questions in chapter 4-6.: )

I’m glad you found this blog useful. I am still working on chapter 3, unfortunately it will be a while before I get to chapter 4, much less chapters 5 or 6.

I am currently an undergrad student majoring in Electrical Engineering (with a keen interest in applied mathematics). Just wanted to say that I’m really inspired by your passion for mathematics! This blog has been on for quite a while now. Perhaps, I will start a blog along similar lines.

You’re being extremely helpful to me, thank you so much!

please send me the solutions of chapter determinants i am in need of it i am taking my P.hd exams

Thanks for doing this! I am a senior going through the same version iof the book, it is my mom’s from college.

When are you going to post 4th chapter and all the rest of them. It has very goos solutions and its very easy to understand. Please post from 4th chapter. Thanx

Great blog with explanations! Very helpful. I am a Machine Learning consultant, but I want to quit being a consultant and become a researcher, so that’s the reason I am learning math.

Good work and thanks!