Question: (a) Let B be the balance at time t of a bank account that earns interest at a rate of r%, compounded continuously. What is the differential equation describing the rate at which the balance changes? What is the constant of proportionality, in terms of r?
(b) Find the equilibrium solution to the differential equation. Determine whether the equilibrium is stable or unstable and explain what this means about the bank account.
(c) What is the solution to this differential equation?
(d) Sketch the graph of B as function of t for an account that starts with $1000 and earns interest at the following rates:
(i) 4%
(ii) 10%
(iii) 15%