1. In linear function and proportional function, you need to find the maximum and minimum values through the range of x values.

2. In the quadratic function, what is 4ac-b to find the maximum and minimum?

When used in questions, most of them are: when X =-2A-B, the maximum or minimum value of y =4a-4ac-b?

A, b and c come from y=ax? From+bx+C。

3. In the chart, the range of values should be based on the side length.

For example, a triangle, the sum of two sides is greater than the third side, and the sum of two sides is less than the third side.

In a right triangle, a? +b？ =c？

There are also some moving points moving on the edge of the graph, so that the moving distance of the moving points cannot exceed the edge length of the graph.

That's basically it. I am not bad at math. Please ask me if I can!

I wish you progress in your study!