1. Teachers pay attention to teaching students thinking methods and cultivating students' thinking ability. In the whole class, teachers are good at inspiring students to explore their own ideas from many angles and aspects, encouraging students to boldly express their different views and giving them affirmation or encouragement in time.

However, while encouraging students to diversify their ideas and algorithms, they also don't forget to teach students general optimization calculation methods, so that their divergent thinking and convergent thinking have developed equally. ?

2. Teachers make students truly become the main body of learning. In the whole teaching process, teachers hardly make any conclusions instead of students. Teachers always guide students to find problems, and then guide students to find ways to solve problems and gain learning experience. ?

3. Teachers boldly break through the original framework of textbooks and use them flexibly.

4. Greatly stimulated students' interest in learning. ?

5. Mathematics comes from life and serves life. The application expansion topic designed at the end of this lesson is to let students use what they have learned to solve problems in life and really practice the basic idea that everyone learns useful mathematics in the new curriculum. ?

Generally speaking, the independent variable x and the dependent variable y have the following relationship.

General formula: y=ax2+bx+c(≠0, a, b and c are constants), then y is called the quadratic function of x.

Vertex: y=a(x-h)2+k(a≠0, a, h and k are constants).

Intersection point (with X axis): y=a(x-x 1)(x-x2)(a≠0, a, x 1, x2 is a constant) x 1, and x2 is the two intersections of quadratic function and X axis.

Contour formula: y=a(x-x 1)(x-x2)+m(a≠0, and (x 1, m)(x2, m) is a constant) x 1, where x2 is the intersection of a quadratic function and a straight line y =