2. The image defined before a is f(a), that is, f(a)=a, if f(a)=2a, then A = 0；; The same situation;

3. The image defined before a is f(a), that is, f(a)=a, where f(a)=a-e, then 0=-e, which is not valid;

4. Lines A and B * * indicate that A and B have a multiple relationship (both directions are possible). Obviously, lines F (a) and F (b) * * *.

The above is my personal opinion. After all, I haven't touched it for so many years, and I'm a little rusty. You'd better find the answer. It shouldn't be difficult.

If you are a student who doesn't understand, you'd better ask your teacher or classmate and the problem will be solved.