exactly...
It is 1.2164
y = x This is a line and a function. Function values are y values.
If you plug in y for the x function, and it equals the answer you got, it is right.
True
Only if it's a function.
yes, it is.
no
f(f(x)) = f(x). Only if f is 1-1 then we have a solution f(x)=x.
All of them
Yes.
Yes, as x-y2=0