A quadratic expression is a specific type of polynomial that follows the form $a{x}^2+bx+c.$ Each term has a specific name.

For an expression in this form to be quadratic, $a$ must be a non-zero number. Consider a few examples of quadratic functions.

Quadratic Expression
$x^2+3x+5$
$5x^2+\frac{1}{4}x+23$
$\frac{3}{5}{x}^2+\frac{1}{2}x+4.3$