You deposit $9000 in a savings account that earns 3.6% annual interest compounded monthly. You also save $40 per month in a safe at home.

a. Write a function [tex]C(t)=b(t)+h(t)[/tex], where [tex]b(t)[/tex] represents the balance of your savings account and [tex]h(t)[/tex] represents the amount in your safe after [tex]t[/tex] years.