# Learning trigonometry on my own.

I have been self teaching myself math beginning with a grade 10 level for a while now and need learn trigonometry from near scratch.

I am seeking both books and perhaps lectures on trigonometry and possibly geometry as some overlap does exist. I am not looking for algebra/precalc textbooks as my algebra knowledge is quite good. The primary goal is to be prepared for both calculus and linear algebra in the future.

I have done some research, but haven't really found much that starts trigonometry from the beginning.

Though I am aware and have used Khan Academy, this is not what I seek. I find things missing from Khan Academy and things are usually taught to generally. I prefer more traditional methods to learning, more doing less watching. However, I am not opposed to other suggestions.

-$Thanks$

$edit:$ Though I love Pauls online notes, it's unfortunate he doesn't have much in the way of trig notes. :(

The Indian mathematician Ramanujan learned his trigonometry from Sidney Luxton Loney's "Plane Trigonometry". Since it's a free Google book, what have you got to lose?

Two years ago I also had to teach myself trigonometry from scratch. I found that the best way to do it was by this book: http://en.wikibooks.org/wiki/Trigonometry

It has plenty of worked examples right after the theory. Hope it helps.

• I was briefly looking at this earlier, does it cover enough to be well prepared for calculus? Also, it doesn't quite seem finished yet. – nitrous2 May 2 '13 at 21:11

This might be of use to you:

http://www.amazon.com/Trigonometry-I-M-Gelfand/dp/0817639144/ref=tmm_pap_title_0?ie=UTF8&qid=1367532520&sr=1-11

The author, Gelfand, was a truly outstanding mathematician. He generously also lent his efforts to the enhancement of secondary school education to present the subjects in a way to prepare students for higher levels of math. You can read a nice assessment in the "Book Description" section.

• I am enjoying this book as well. Gelfand's goal seems to be (in part) to make the trigonometric relationships objects in their own right that deserve to be understood, as opposed to simply functions that are applied to find the length of a side of a triangle (for ex.). "But each of these results is also important in its own right, without being 'pre-' anything." Just reading the preface of this book makes me wish I could go back in time and hit my 14-year-old self over the head with it. – user27634 Jul 11 '13 at 3:02
• @user27634 Good for you. All the best, – user12802 Jul 11 '13 at 10:29

You should get a college trigonometry book for a trigonometry course. Go on the website of your local community college and find the course Trigonometry. It is a 3 credit course with (usually) college algebra as its prereq. They will list the book they use. Then go get the outdated version from some online store because it is much cheaper, but essentially covers the same. You may even visit your college and ask a faculty member for an outdated edition. Math people are very kind (!!) and sometimes they may give you just one either to borrow or just to have it. Good luck

• And yes, those books will prepare you for the Calc sequence – imranfat May 2 '13 at 21:18

A few more recommendations:

Lyman Kells Trig (I like the Education Manual version as it is SELECTED FOR APPROPRIATENESS FOR SELF STUDIERS): https://www.amazon.com/Education-Manual-spherical-trigonometry-tables/dp/B006FKGLDE

(You could skip the spherical part unless you get the proverbial hair)

https://www.amazon.com/Theory-problems-first-college-mathematics/dp/B0007DPVM2

Contains more than just trig: very nice, older, Schaum's