Su Jiaoban's Quadratic Function, the second volume of the ninth grade.

People's education edition quadratic function ninth grade first volume.

The basic expression of quadratic function is y=ax? +bx+c(a≠0). The highest degree of a quadratic function must be quadratic, and the image of a quadratic function is a parabola whose symmetry axis is parallel or coincident with the Y axis.

Key points of knowledge

1. Understand the meaning of the function.

2. Remember several expressions of the function and pay attention to the differences.

3. General formula, vertex, intersection, etc. , distinguish the differences of symmetry axis, vertex and image, and y decreases (increases) (increases or decreases) with the increase of x.

4. Understand the function image with practice.

5. When calculating, remember to take the range of values when looking at the image.

6. It changes with the change of image understanding number. Test sites and examples of quadratic function

Quadratic function knowledge can be easily integrated with other knowledge, thus forming a more complex comprehensive topic. Therefore, the comprehensive question based on quadratic function knowledge is a hot topic in the senior high school entrance examination, which often appears in the form of big questions.