(logic) A well-formed formula which has not been made by combining simpler well-formed formulas by means of logical connectives.

(organic chemistry) A skeletal formula, especially a schematic representation of benzene as a hexagon made up of alternating single and double lines that represent alternating single and double bonds

(chemistry) A structural formula which is reduced (i.e., skeletal) in the sense that carbon atoms forming the backbone of the structure (esp. of an organic compound) are not labeled — they are shown simply as vertices — and hydrogen atoms are not shown at all (except those which are bonded to heteroatoms, or the exceptionally labeled carbon atoms) but heteroatoms are always labeled. (Labels of labeled hydrogen atoms are written next to labels of the atoms that they are bonded to, without a bond drawn between them. If there are several labeled hydrogen atoms bonded to the same atom then they are written as an H with a subscript for their number.) Carbon atoms which are (optionally) labeled tend to be in reactive extremities of the molecule, not the backbone of it.

(trigonometry) law of cosines

(trigonometry) law of sines

(physics) A formula describing the mean energy loss per distance travelled of swift charged particles traversing matter (or alternatively the stopping power of the material).

(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.

(chemistry) A simplified structural formula that does not show the individual atoms' relative position in space

Abbreviation of Bailey-Borwein-Plouffe formula.