The inverse of f(x) is h(x). The composition of f and h is written f[h(x)]. What does f[h(x)] equal?
Hint: Think of a simple problem like f(x) = x + 3. Then the inverse, h(x) would be h(x) = x - 3. What would the composition f[h(x)] equal in this example?
f(h) means the function operates on h.
f(h)= h+3= x-3+3=x
Notice that
h(f)= f-3=x=3-3=x