
Re: NDSolve curve  obtain single value from curve at t:=d
Posted:
Aug 15, 2012 3:34 AM


Am 14.08.2012 10:23, schrieb design: > Customized annuity applet; > I need to find the value of sol1 at t = d; > d, age, remaining life, fundrate, (and others) are all sliders; > Overall apples is working well > > d = age + remainingLife; > eqn1 = y'[t] == fundRate/100*y[t]  annuityAmt;=E2=80=A8sol1 = y[t]/. NDSolve[{eqn1, y[age] == startValue}, y[t], {t, age, 110}]; > > I have tried the sol1 iteration with {d,d,110} and many other approaches to no avail. > > Suggestions appreciated!! > Hi,
DSolve[{y'[t] == fundRate/100*y[t]  annuityAmt, y[age] == startValue}, y[t], t]
> {{y[t] > (1/fundRate) E^(((age fundRate)/ 100)) (100 annuityAmt E^((age fundRate)/100)  100 annuityAmt E^((fundRate t)/100) + E^((fundRate t)/100) fundRate startValue)}}
doesn't help?
In simple cases, try the exact solution. Even if the calculation needs a while (not for this differential equation), it's worth it.
Peter

