Abank account earns 5% annual interest compounded continuously. you wish to make payments out of the account at a rate of $12,000 per year (in a continuous cash flow) for 20 years. i) write a differential equation describing the balance b = f (t), where t is in years. ii) find the solution b = f (t)to the differential equation given an initial balance of b0 in the account. iii) what should the initial balance be such that account has zero balance after precisely 20 years?