Continuation of Example 4, Section 1.2: Find the equilibrium value of the digoxin mo...

Continuation of Example 4, Section 1.2: Find the equilibrium value of the digoxin model. What is the significance of the equilibrium value?

REFERENCE:

EXAMPLE 4 An Investment Annuity

Return now to the savings account problem and consider an annuity. Annuities are often planned for retirement purposes. They are basically savings accounts that pay interest on the amount present and allow the investor to withdraw a fixed amount each month until the account is depleted. An interesting issue (posed in the problems) is to determine the amount one must save monthly to build an annuity allowing for withdrawals, beginning at a certain age with a specified amount for a desired number of years, before the account’s depletion. For now, consider 1% as the monthly interest rate and a monthly withdrawal of $1000. This gives the dynamical system

Now suppose we made the following initial investments: