(exobiology) A formula for calculating the probability of civilizations existing elsewhere in the Milky Way galaxy and of their ability to communicate with Earth.

(algebra) A mathematical equation in which one or both sides is an algebraic expression, such as 2x + 7y = 3.

(algebra) Any algebraic equation in which one or both sides are in the form of a polynomial.

(chemistry) a symbolic representation of a chemical reaction; reactants are represented on the left, and products on the right

(number theory) The Diophantine equation x²-my²=1 for a given integer m, to be solved in integers x and y.

(mathematics) a set of equations that defines the coordinates of the dependent variables (x, y and z) of a curve or surface in terms of one or more independent variables or parameters

(mathematics) An equation involving a function f(x) and integrals of that function to be solved for f(x)

(astronomy, celestial mechanics) the mathematical relationship between the mean anomaly (M) and the eccentric anomaly (E) of a planet in an elliptical orbit with eccentricity (𝜀). M=E-𝜀· sin (E).

(mathematics) a set of equations of motion of a mechanical system which relate the kinetic energy of the system to its generalized coordinates

(chemistry) An equation which approximates the dependence of the rate of any chemical reaction on the temperature.