Reddit mentions of Just-in-Time Algebra and Trigonometry for Calculus (4th Edition)

Just-in-Time Algebra & Trigonometry for Calculus, by Guntram Mueller and Ronald Brent, is a great book to review the things from precalculus and trigonometry that you need to know for calculus. The topics are arranged roughly in the order that you'll need to use them in a typical calculus course.

Run.

No, I'm only joking. I just took Calc, and the Calculus part is relatively easy, it's the Algebra/Trig components that trip people up. I'm not saying Calculus is easy, you'll still have to put the work in. But review algebra II and Trigonometry because they will make things a lot easier.

The following isn't a comprehensive list, just the stuff that I remember I had to know.

• For algebra, review polynomial operations, functions and graphing, exponents and radical rules.
  
  
• For trig, review the unit circle, how to find triangle angles and sides (particularly 45 degree and 30 degree angles), fundamental trig identities, and sin, cos, tan, etc.
  
  This was the book my school recommended for brushing up on Algebra and Trig
  
  For extra help, Prof Leonard and Patrickjmt were immeasurably helpful. They explained concepts much better than my professor.
  
  Good luck!
  
  

I use Just In Time whenever I run across a calc student who is weak in trig and algebra.

It is true that is why people tend to have trouble with calculus in my opinion. I think it's good that you want to be prepared, but I think you should look ahead more than behind considering you're a math major who got an A in their algebra course. You're not the typical student who struggles because of algebra mistakes.

But, if you twisted my arm for a recommendation, I quite like this one (besides some of the orderings of the topics): Just-in-Time Algebra and Trigonometry for Calculus

I'm in the exact same situation as you. Dropped out when I was 16 and have only taken one math class since.

I'm using Khan Academy to brush up on basic stuff and then once I'm at precalc level I'm going to use this book as well. Also, check out syllabi for Calculus I classes at the school you'll be going to. A lot of the time they'll have prerequisite reviews with example problems, to get an idea of the level of knowledge you need to take the class.