I'm assuming you're not a math/engineering major? If you are it's ok too, the range of questions that could pop up on the GRE is pretty wide. Depending on when you plan to take the GRE, you should just do as many practice problems as possible, and if you have time, before you even begin to practice, purchase a study guide for something around $25-$40 and go through their quantitative review. The Kaplan GRE prep book does a pretty good job. I never ran into a situation where I had to use the quadratic formula and I did over 300 practice quantitative problems from the Kaplan book in one week, as well as the 80 extra I took on the powerprep tests. Then again if I did run into a situation where I had to use the quadratic I probably would have recognized it, if you're not an engineering or math type of major then it's understandable, it's a pretty simple formula to memorize, whether you have to memorize it or not I'm not sure, sorry that I couldn't be of more help. One thing I can say is make sure you know all of the equations for area for basic shapes, such as circles which pop up a lot, and obviously your squares, rectangles and triangles.