What are the formulas you should have memorized for the math section of the ACT?
Thanks so much for any help!
I can’t think of many off the top of my head, but the ones that come to mind are:
- Pythagorean formula
- distance formula
- point-slope form and y = mx + b
- 30-60-90 and 45-45-90 triangles
Most of these you learn in Alg I or geometry so it’s likely you already know them, but it’s good to brush up. I know I missed at least one problem on my first ACT because I couldn’t remember whether the distance formula was + or -. Needless to say, I brushed up before I took the test again.
@whitespace I tend to not think of the “distance formula” as a formula but instead as an equivalent statement to the Pythagorean theorem. Because it really is exactly the same as the Pythagorean theorem.
A couple more to add - trig and trig formulas (e.g. sin^2 x + cos^2 x = 1, which is also the Pythagorean theorem, but also formulas for sin(a+b), cos(a+b), law of sines, law of cosines) since those tend to pop up.
@MITer94 Yes, I think of it that way now, too. When I took the ACT two years ago, though, I hadn’t quite grasped that concept yet.
I would also look at solutions for solving systems of equations. Substitution always worked really easily for me, but I know there are other methods that certain people prefer.
On a recent ACT I took, there was a reasonably challenging question on arithmetic/geometric sequences.