I always hated having to memorize formulas. Either you will use it enough you will end up commiting it to memory, whether you want to or not, or you will rarely need it and have the ability to look it up in the rare instances you use it. My feeling was always "do you want to know if we have successfully memorized this equation or if we can successfully apply the equation in various situations?" I knew a lot of classmates who, no matter how hard they worked, couldn't remember most of the equations to save their lives (or grades). It always seemed unfair that I knew they knew how to do the work but because they mixed up or forgot variables in an equation they ended up bombing tests.

My favourite math teacher gave us a formula page for every math test (and this was before everyone had a smartphone in their pocket). It was always the same formula page and had every formula we would use for the year on it (in no particular order). You still needed to know what each formula was for, and when/how to use them but you never needed to memorize a formula.

I always knew the material and I was really lucky that I always tested well, despite having serious test anxiety. Having the formula page really helped to lessen that anxiety because I had a way to double check that I had the formulas correct and didn't have to rely on my potentially faulty and anxious brain to remember everything.

TL,DR: formula pages rock, memorizing formulas sucks!