# Coefficient

multiplicative factor involved in some term of a polynomial, a series, or an expression

In mathematics, a coefficient is a constant multiplicative factor of a certain object. For example, the coefficient in 9x2 is 9. A coefficient can also be a variable such as ${\displaystyle a}$, ${\displaystyle b}$ and ${\displaystyle c}$.[1][2]

The English Wiktionary has a dictionary definition (meanings of a word) for: coefficient

The object can be such things as a variable, a vector, a function, etc. In some cases, the objects and the coefficients are indexed similarly, leading to expressions such as:

${\displaystyle a_{1}x_{1}+a_{2}x_{2}+a_{3}x_{3}+\cdots }$

where an is the coefficient of the variable xn for each n = 1, 2, 3, …[3]

## References

1. "Compendium of Mathematical Symbols". Math Vault. 2020-03-01. Retrieved 2020-08-15.
2. "Definition of Coefficient". www.mathsisfun.com. Retrieved 2020-08-15.
3. Weisstein, Eric W. "Coefficient". mathworld.wolfram.com. Retrieved 2020-08-15.