Verify that f has an inverse. Then use the function f and the given real number a to find (f −1)'(a).

f(x) = x3 − 1, a = 7
(f −1)'(7) =

Pepe and leo deposits money into their savings account at the end of the month the table shows the account balances. if there pattern of savings continue and neither earns interest nor withdraw any of the money , how will the balance compare after a very long time ?