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mathematical expression of the second degree in one or more unknowns (see polynomialpolynomial,
mathematical expression which is a finite sum, each term being a constant times a product of one or more variables raised to powers. With only one variable the general form of a polynomial is a0xn+a1x
). The general quadratic in one unknown has the form ax2+bx+c, where a, b, and c are constants and x is the variable. A quadratic equation ax2+bx+c=0 always has two rootsroot,
in mathematics, number or quantity r for which an equation f(r)=0 holds true, where f is some function. If f is a polynomial, r is called a root of f; for example, r=3 and r
, not necessarily distinct; these may be real or complex (see numbernumber,
entity describing the magnitude or position of a mathematical object or extensions of these concepts. The Natural Numbers

Cardinal numbers describe the size of a collection of objects; two such collections have the same (cardinal) number of objects if their

gives the roots of any quadratic equation in terms of its coefficients a, b, and c. The expression b2−4ac is called the discriminant and vanishes when the two roots coincide. If a, b, and c are real and the discriminant is not less than zero, the roots are real.