Answer:
3
Explanation:
if we combine a function f(x) and its inverse f-¹(x), the result will be x
f-¹(f(x)) = f(f-¹(x)) = x
you can try for any function, i.e.
f(x) = 2x + 1
f-¹(x) = (x-1)/2
f-¹(f(x)) = (2x + 1 - 1)/2 = x
f(f-¹(x)) = 2((x-1)/2) + 1 = x - 1 + 1 = x