A quadratic equation is a polynomial equation whose degree is two. Quadratic equations become a major topic in Algebra.

 A quadratic function graphed on a coordinate plane.

Although quadratic equations can take many forms, there is a general form that is used most commonly.

(1)
$$ax^2+bx+c=0$$

In this form, x is the variable of the polynomial. The a, b, and c are the coefficients of the x variable where a is the quadratic term being of the second power, b is the linear term, and the c is the constant term. Of these terms, a cannot be equal to zero or else the equation no longer can be considered quadratic.