The original function can't directly see that it needs to be differentiated first, so that the derivative function is equal to 0, and then X can be calculated. If you bring the obtained x into the original function, you will get the extreme value. If we want to judge whether it is the maximum value or the minimum value, we should bring the nearby x value into the derivative function, such as X = 1 extreme value. Then substitute x=0 and x=2 into the derivative function respectively. If you substitute x=0 to get a negative number and x=2 to get a positive number (f' (x) < 0 decreases and f' (x) > 0 increases), then f( 1) is the minimum value and f( 1) is the maximum value.

According to your graph, we can know that the graph on the topic is the graph of the derivative function f'(x). When f'(x)=0, there is an extreme value, and then the above method of judging the maximum value and the minimum value can determine that C is wrong. At present, A and B regard f'(x) as an ordinary function instead of the derivative function of f(x) x 1, where left decreases and right increases, and left increases and right decreases, which is also a increasing function.