Find the stagnation point, x 1, x2.

Y''>0, the function gets the minimum value at the change point.

Y''<0, the function gets the maximum value at the change point.

Generally speaking, the derivative of the function y=f(x) is still a function of x, so the derivative y' = f' (x) is called the second derivative of the function y=f(x). Graphically, it mainly shows the concavity and convexity of the function.

Tips for learning mathematics:

1, you should be good at thinking when learning mathematics, and the answers you come up with are far more impressive than those others say.

2. Prepare well before class, so that we can better digest and absorb the unknown knowledge points in math class.

3, the mathematical formula must be memorized, and it must be deduced and can be deduced.

4. The most basic thing to learn mathematics well is to master the knowledge points of textbooks and exercises after class.

5. 80% of the scores in mathematics come from the basic knowledge, and 20% of the scores are difficult, so it is not difficult to test 120.