初中数学知识点2(国外英文资料).docVIP

初中数学知识点2(国外英文资料) B, equations and inequalities 1 equations and equations Equation of one dollar: in an equation it contains only one unknown, and the exponent of the unknown is 1. Such an equation is called a unary equation. An algebraic formula on which two sides are added or subtracted or multiplied by or divided by (not 0), and the result is still an equation. The solution steps of one equation: to the denominator, revenuer, the unknown coefficients of the merger of similar items, 1. An equation of two variables: the equation with two unknowns and the number of terms containing unknown numbers is 1, called the two yuan one equation. Two yuan one equation group: the equations of two two variables one time equation are called the two yuan one equation group. The value of a set of unknowns suitable for a two yuan one equation is called a solution of the two yuan primary equation. The common solution of each equation in the two variables system is called the solution of the two variables equation. The method of solving two yuan one equation set: substitution elimination method / addition and subtraction method. An equation of two variables: the maximum coefficient of the term of an unknown number is 2 1) the relation of the two functions of the two equation of a dollar We have already learned the quadratic function (i.e. parabola), he also has a deep understanding, as in the image representation method, and so on, in fact, quadratic equation with one unknown quadratic function can also be used to represent, in a special case of quadratic equation with one unknown is quadratic function, it is when the Y 0 when it constitutes a quadratic equation with one unknown. If it is expressed in a plane Cartesian coordinate system, the unary two equation is the intersection of the image and the X axis in the two function. That is, the solution of the equation 2) the solution of the two equation of a dollar As we all know, quadratic function vertex type (-b/2a, 4ac-b2/4a), which