Example

Multiplying f(x)=x+2f(x) = x + 2 and g(x)=x23x4g(x) = x^2 - 3x - 4

To find the product function (fg)(x)(f \cdot g)(x) for the polynomial functions f(x)=x+2f(x) = x + 2 and g(x)=x23x4g(x) = x^2 - 3x - 4, substitute the expressions into the multiplication formula: (fg)(x)=(x+2)(x23x4)(f \cdot g)(x) = (x + 2)(x^2 - 3x - 4). Multiply the polynomials by distributing: x(x23x4)+2(x23x4)x(x^2 - 3x - 4) + 2(x^2 - 3x - 4). This expands to x33x24x+2x26x8x^3 - 3x^2 - 4x + 2x^2 - 6x - 8. Combining the like terms yields the final product function: (fg)(x)=x3x210x8(f \cdot g)(x) = x^3 - x^2 - 10x - 8.

0

1

Updated 2026-04-29

Contributors are:

Who are from:

Tags

OpenStax

Intermediate Algebra @ OpenStax

Ch.5 Polynomials and Polynomial Functions - Intermediate Algebra @ OpenStax

Algebra