ACT Tips and Advice Post
Google "ACT Math Formulas" and you get a grab-bag of subpar results, including an old PDF from 1996 and two popular but glaringly incomplete lists of ACT Math Formulas. The fact is that the ACT Math section has many more required formulas and concepts than the ones you can find easily online.
And hey, while we're at it, let's try for a full list of EVERY math formula and concept that shows up on the ACT. If you feel that I've left anything out, then please let me know at firstname.lastname@example.org.
That being said, the fewer formulas you need to remember, the more you can focus on technique, and good technique is the true key to an excellent ACT score. I don’t teach my students unnecessary formulas because I can teach them to find the answers using a more logical approach to the problem.
For more information you can read my ACT Action Plan.