(mathematics) A formula that connects trigonometry and complex numbers, stating that, for any complex number (and, in particular, for any real number) x and integer n, big ( cos (x)+i sin (x) big )ⁿ= cos (nx)+i sin (nx), where i is the imaginary unit.

An empirical formula estimating the average velocity of a liquid flowing in a conduit that does not completely enclose the liquid, i.e. an open channel.

Alternative form of Kekulé formula

(photography) A photographic format in between full-frame or 35mm (36 × 24 mm) and large format (127 × 102 mm).

(photography) A photographic format of 4 × 5 inches (102 × 127 mm) or larger. / (wine) A bottle size larger than the standard 750 mL. / Used other than figuratively or idiomatically: see large, format.

(fluid dynamics) A formula that describes the mean flow velocity of steady, turbulent open-channel flow.

(mathematics) An equality involving Fourier coefficients of automorphic forms, with the coefficients twisted by additive characters on either side. It can be regarded as a Poisson summation formula for non-abelian groups.

(biology, archaic) The formation of several cells from and in the protoplasm of the mother cell.

(mathematics) Synonym of Stirling's approximation

(mathematics) A formula expressing the sum of the pth powers of the first n positive integers as a (p + 1)th-degree polynomial function of n, the coefficients involving Bernoulli numbers.