All of them
it equals 1
3
F(x)=[x^2]+1
It is f(x) = -x^2.
All of them
it equals 1
f(x)=x+1 g(f(x))=x f(x)-1=x g(x)=x-1
3x = 45 x = 15
No, x + x equals 2x. x times x equals x2. (x times x equals x squared.)
It is f(x) = 7/x.
-2
Force equals Mass times Acceleration, or F = M x A
No, f(x) is not the inverse of f(x).
If you know the values of "f" and "x", you just do the multiplication.Please note that if you see something like: y = f(x) this usually does NOT mean that f and x should be multiplied; it means that "y" SOMEHOW depends on "x", i.e., it is a function of "x". To calculate the value of this function, you need to know how exactly the function is defined.
3
f(f(x)) = f(x). Only if f is 1-1 then we have a solution f(x)=x.