An annuity is a fund into which one makes equal payments at regular intervals. If the fund earns interest at rate r compounded continuously, and deposits are made continuously at the rate of d dollars per year (a continuous annuity), then the value y(t) of the fund after t years satisfies the differential equation y' = d + ry. + (Do you see why?) Solve the differential equation for the continuous annuity y(t) with deposit rate d = $9000 and continuous interest rate r = 0.02, subject to the initial condition y(0) = 0 (zero initial value). y = X Need Help? Watch It Master It