The finale of quadratic function in mathematics of grade three usually includes solving parabolic analytical formula, finding the maximum value, finding the coordinates of intersection point with coordinate axis and so on. The relevant explanations are as follows:

1. In the plane rectangular coordinate system, the image of the quadratic function y = ax 2+bx+c intersects the X axis at two points, A and B. The coordinate of point A is (-3,0), point B is on the left side of the origin, and intersects the Y axis at point C (0,3), and point P is a moving point on the parabola above the straight line BC.

2. In the plane rectangular coordinate system xOy, the straight line AB intersects the X axis at point A and the Y axis at point B, and the straight line AB passes through the intersection points A and B of parabola Y = AX 2 and straight line y=kx+b(k is a natural number), where the coordinates of point A are (-2, 1) and the coordinates of point B are (4).

3. It is known that the parabola Y = AX 2 and the straight line y=kx+b(k is a natural number) intersect at point A and point B, where the coordinate of point A is (-2, 1), the parallel line passing through point A on the X axis intersects with the parabola at point E, and point D is a moving point between points B and E on the parabola, and its abscissa is T. After passing through it,

Skills of solving the finale problem

1, simplification of miscellaneous questions: decompose a complex problem into a series of simple problems, divide a complex figure into several basic figures, find similarities, find right angles, find special figures and solve them slowly. Starting from the known conditions, combined with options, through observation, analysis, speculation and calculation, obviously wrong answers are eliminated one by one, thus narrowing the scope of thinking and improving the speed of solving problems.

2. The problem of motion is static: for dynamic graphics, first find out the constant line segments and angles, whether there are ever equal line segments, ever congruent graphics and ever similar graphics, and all operations are based on them, then find out the relationship between the changing line segments and solve it slowly with algebra.

3. Specialization of general problems: Some general conclusions cannot be solved. First look at special cases, such as the moving point problem, and see how it moves to the midpoint, how it moves to the vertical, and how it becomes an isosceles triangle. Find out the conclusion first, and then solve it slowly.