Hello from MrBillDoesMath!
Answer: f(g(t)) = t
Discussion:
A function and its inverse "undo" each other. Suppose that
f(t) = t^2 and g(t) = t^ (1/2)
Then
A B C
g(f(t)) = g (t^2) = (t^2) ^ (1/2) = t
A: substitute the definition of f(t), that is t^2, in the equation
B: g(t) takes the square root if its argument
C: The square root of a squared item is the item itself.
Regards, MrB