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 }.

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