1 refers to two functions f( 1-x) and f( 1+x) obtained from the transformation of f(x). Discuss the relationship between these two functions. The relationship you gave should be wrong. I think the symmetry of these two function images about the straight line x= 1 is correct.

Only f(x) is considered, but f(x) satisfies this relationship, which shows that the image of f(x) is symmetrical about the straight line x= 1.

The proof of linear symmetry should be done according to the definition. For example, 2 can be considered like this. Let's take any point p (x, f(x)) on the image of f(x), and its symmetric point about x= 1 is q (2-x, f(x)). Let's explain that q is on the image of f (x) and in f (1-x) = f (65438). In addition, the symmetry of f(x) is explained.