First, let's talk about how to draw a picture. This power multiplication continuous function can be drawn in one stroke. We can find 0 points on the number axis, 1, 2, 3, 4 and 4 points. When X tends to infinity, obviously Y is infinite, so we draw from the right of x=4, x= 1, 2, 3, 4. And symmetric) as shown in the figure, in the same way, when encountering an even power, it crosses when encountering an odd power (x-3 is an odd power, and the domain symbols are the same size). Pay attention to drawing as smoothly as possible to prepare for the second step. I drew it with the mouse, but it's not good. You can use strokes.
In the second part, just look at the picture and do the questions. The inflection point is the separation point with different concavities and convexities. Obviously, the even point in the picture is impossible, because the left and right sides are symmetrical, and the concave and convex in the field of vision must be the same. Looking at the picture again, it is obvious that x=3 is the inflection point.
It's that simple. I solved the problem in one minute. It is very important to make a fuss about high marks in mathematics. It is very skillful to make a fuss. I hope the landlord will come on. You can keep asking me questions.
Supplementary answer: Hello? HKRichest, a multiple-choice question has its own reasons. Is it meaningful to make it a big problem? It's just a few derivatives. That's not how big questions come out. Who can't get the derivative? This is just a calculation. I believe the landlord doesn't want you to tell him how to get the derivative step by step. About the two you wrote, the first one is x=-2, and the second one is X = B. Is there a problem? If you want to get high marks, what kind of questions and methods should you use? It is not advisable to make a fuss with a big problem (unless, of course, there is only one method). How can I get a score for the postgraduate entrance examination? Thank you. It's just a discussion. It won't hurt the peace.