I'm in grade three, too, and I just finished learning it now. Let's sum up:

1. Form of quadratic function: general form, vertex, intersection (you should know this).

There is also a formula for finding the vertex.

The above is the foundation. There is also an analytical formula with points.

The most important function is image. Now we are exposed to many problems, all of which are image problems. This is crucial. I have encountered several problems before, and I have asked them myself. I can show you some types.

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First of all, you need to be familiar with the opening direction, vertex coordinates and symmetry axis. When you see a topic with images, you don't have to think about it. These are basically marked. Then combine the table.

Another point of the function image is translation.

You just need to remember these words: up plus down minus, left plus right minus! ! !

When you know the value of x, that is, the axis of symmetry, you can judge the positive and negative of b according to the image. Because X=-b/2a C depends on whether the focus with the Y axis is on the positive or negative half axis.

Then the application of quadratic function.

The most common ones are buying and selling, and what is sold less for every dollar added.

This is very common. But sometimes the key is to minimize inventory, so it is very important.

There is also throwing things, so that you can find a parabola. You will use the highest and lowest points, so you will definitely find the vertex.

There is also a kind of topic: the problem of moving points.

Now I have handed it in. I have done this area problem several times. That means moving. If it is an irregular figure, it is common to divide it into triangles, and the topic will definitely let you find the maximum area or minimum value. You should find more problems to do.

Because writing the topic is too troublesome, I won't say much.

Someone may suggest that you buy a book.

This is my general summary. I hope it helps you. But it's entirely up to me. Actually, I don't think it's useful to find a topic online.

It's too difficult to buy things by yourself and do it by the teacher. If you look online, there are many versions, some of which are not suitable. You have to suit yourself.

If you ask questions, examples in the book are the best.

But I see in your file that you are from Shanghai, so I can't help you how to say it in the book. Our books are a little different. But the starting point of knowledge points is the same. Start (a disease) ...

I think the first courseware for men on the first floor is not bad, so I can sum it up ~