There are a number of formulas that are absolutely essential to success on the math portion of the ACT. It is, however, not only important to memorize them; the onus is on students to develop a deep and sincere understanding of how to apply them. Join Huzefa as he goes through each of the formulas with a succinct explanation of how to apply them, along with the sharing of an article on precisely how to go about effectively understanding these various formulas.

http://www.mathsdoctor.co.uk/blog/10-top-tips-to-help-memorise-maths-formulae/
http://blog.prepscholar.com/the-31-critical-act-math-formulas-you-must-know