# General Form of Quadratic Function

General form of a quadratic function is $f\left(x\right)=a{x}^{2}+bx+c$ where a, b, and c are constants and a ≠ 0, and x as a variable.

Example:

Determine which of the following is a quadratic function.
1. $f\left(x\right)=\left(5x-3\right)\left(3x+8\right)$
2. $f\left(x\right)=2\left(3x+8\right)$
3. $f\left(x\right)=\frac{5}{2{x}^{2}}$
$\begin{array}{l}f\left(x\right)=\left(5x-3\right)\left(3x+8\right)\\ f\left(x\right)=15{x}^{2}+40x-9x-24\\ f\left(x\right)=15{x}^{2}+31x-24\end{array}$
$\begin{array}{l}f\left(x\right)=2\left(3x+8\right)\\ f\left(x\right)=6x+16\end{array}$