- For the case of more than one variable, see Conic section or Quadratic form.
In
elementary algebra, a
quadratic equation (from the
Latin quadratus for "
square") is any equation having the form
where represents an unknown, and , , and represent known numbers such that is not equal to . If , then the equation is
linear, not quadratic. The numbers , , and are the
coefficients of the equation, and may be distinguished by calling them, respectively, the
quadratic coefficient, the
linear coefficient and the
constant or
free term.