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Faux Erik Picture
Not me, but a good picture!

I hope that you have found the material on this web site to be useful, whether you are a student, teacher, tutor, or perhaps someone who just happens to like math and Viking hats. Most of the content here has to do with SAT math and physics, with some help for those taking the ACT as well. If you look around this site, you'll find a lot about these tests: everything from the date of the very first SAT, to whether you should use a mechanical pencil on the SAT or ACT. (To save you some time looking: June 23, 1926, and "No".)

When I first thought about putting SAT guides up on erikthered.com in 2007, I figured that these types of things could easily be found elsewhere on the Internet, but I was surprised to find that they were not. At least, that is, if you wanted free, printable, shareable, SAT and ACT math help guides. As a math and physics tutor, I needed materials (with good quality typesetting and decent figures) that students could grab online, print out, write notes on, copy, and give to other people if they wanted to.

Erik Jacobsen
Me, but not a good picture?

I think the value of a tutor should mostly derive from his or her ability to teach and encourage learning, so I'm happy to provide these materials for other teachers and tutors to use as well. Commercial use is fine: all the HTML and PDF content here is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported License.

Basically, this license says: feel free to share and make copies of this content, or even modify it, as long as you use the same, similar, or compatible license. Also, please leave in an attribution to me (Erik Jacobsen) and to this web site, erikthered.com/tutor/. If you are simply using these materials without any modifications then there really is no restriction on how you use them. (My web site is already mentioned in all the HTML and PDF files.) I've tried to put some care into making good quality guides, and I hope that they are completely mistake-free. But, if that isn't the case, or if you have any suggestions, please let me know. If you are a teacher or tutor using my materials, I would love to hear from you! If you are taking the SAT or ACT and have a question, let me know! I'll try to answer as many questions as you have.

Why Erik the Red? If you have reached this page looking for information about the Viking explorer, I'm afraid that there is not much here about him. But, I'm sure that Wikipedia will do the job just fine. My hair gets a bit of red in it in the summer, I'm half Norwegian, and my first name is Erik, so it does make sense, at least a little bit.

A little bit of advertising: I'm a private math and physics tutor in the Summit, NJ area. I specialize in SAT and ACT math, ACT science, pre-calculus and calculus, and physics; I've been doing this for a living since 2007. Please don't hesitate to contact me if you live in this area and you or your child needs help in these subjects. You can find me @ErikTheRedTutor on Twitter, or you can reach me privately at mptutor < at > erikthered.com (replace the "< at >" with the usual at-sign).

— Erik Jacobsen, Ph.D.

The pi's the thing /
Wherein I'll catch the circumference of the ring.


  — Hamlet, using math to play Frisbee™