formulaformula, in mathematics and physics, equation expressing a definite fixed relationship between certain quantities. The quantities are usually expressed by letters, and their relationship is indicated by algebraic symbols. For example, A = π r ^{2} is the formula for the area A of a circle of radius r, and s = 1/2 at 2 is the formula for the distance s traveled by a body experiencing an acceleration a during a time interval t. The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved. See more Encyclopedia articles on: Mathematics 
