Personally, I agree with OldFritz, it is absolutely unnecessary to burden one's brain with abstruse formulas. For example, I am pretty certain that a very very small subsection of 99% scorers would know the expression for the Area of a circle circumscribing equilateral triangle. The GMAT doesn't really emphasize that. The only formula that I have ever used on the GMAT is the expression for the area of an equilateral triangle with side s, [sqrt(3)*s^2]/4. Other than that a problem solving mind set, along with the ability to think and approach a problem in multiple ways is probably more relevant for the GMAT.
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