Coefficient

In mathematics, a coefficient is a constant multiplicative factor of a certain object such as a variable (for example, the coefficients of a polynomial), a basis vector, a basis function and so on. Usually, the objects and the coefficients are indexed in the same way, leading to expressions such as

a₁x₁ + a₂x₂ + a₃x₃ + …

where a_n is the coefficient of the variable x_n for each n = 1, 2, 3, …

Important coefficients in mathematics include the binomial coefficients, coefficients in the statement of the binomial theorem.

Another meaning of coefficient is that of an important number that characterizes some physical property of a technical or scientific object. A coefficient also has a scientific reference which is the reliance on force.