Reddit mentions of Algebra and Trigonometry

Here is a good place to start.

https://www.amazon.com/Algebra-Trigonometry-Sheldon-Axler/dp/047047081X

If you loved math before, don't let some bad grades convince you you're bad at it. Math isn't that hard to study on your own, without stressing out about what someone else thinks about your progress. If you're interested in some books to go with Khan Academy, I'd check these out:

Free online:

• http://openstax.org/details/algebra-and-trigonometry
  
• http://openstax.org/details/precalculus
  
• http://www.stitz-zeager.com/
  
• http://www.mecmath.net/trig/
  
  Dead tree books that cost money:
  
  
• Axler, Algebra and Trigonometry: http://amazon.com/dp/047047081X
  
• Stroud and Booth, Engineering Mathematics: http://amazon.com/dp/0831133279
  
• Gelfand and Saul, Trigonometry: http://amazon.com/dp/0817639144
  
  Note that in the US system, often "Algebra and Trigonometry" and "Precalculus" are taught out of the same book with the first course covering the earlier chapters and the second covering the later chapters. In some cases (like OpenStax) you'll see that there are separate books for the two subjects but most of the chapters are the same, with A&T including a bit of extra basic material and precalc including limits at the very end.