Coefficient

In mathematics, a coefficient is a multiplicative factor that belongs to a certain object such as a variable, 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 + …

An important coefficient in mathematics is the binomial coefficient.

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Another meaning of coefficient is that of an important number that characterizes some property of a technical or scientific object.