Vieta theorem formula: unary quadratic equation ax? +bx+c=0(a, B, C are real numbers, a≠0), where are the two X's? 、x？ The relationship is x? +x？ =-b/a，x？ x？ =c/a .
The reasoning process of this formula is as follows:
The most important contribution of Vieta's theorem is the promotion of algebra. Firstly, he systematically introduced algebraic symbols, promoted the development of equation theory, replaced unknowns with letters, and pointed out the relationship between roots and coefficients. Vieta's theorem laid a foundation for the study of the unary equation in mathematics, and created and opened up a broad development space for the application of the unary equation.
Vieta theorem can be used to quickly find out the relationship between the roots of two equations. Vieta theorem is widely used in elementary mathematics, analytic geometry, plane geometry and equation theory.