For example, in this problem, the derivative function G (x) = 2x 2-2ax+ 1 is a quadratic function with an upward opening, so we can discuss its pros and cons with images. Because A is an uncertain number, when the discriminant is less than 0, A 2: = 2, and g(x) is positive or negative. Therefore, the solution when g(x)=0 is required, and the increase or decrease range can be judged by the image, but the premise should be paid attention to: the amplitude of A. 。
I wonder if you are satisfied with this answer?