Re: NDSolve curve - obtain single value from curve at t:=d

*To*: mathgroup at smc.vnet.net*Subject*: [mg127700] Re: NDSolve curve - obtain single value from curve at t:=d*From*: Peter Pein <petsie at dordos.net>*Date*: Wed, 15 Aug 2012 03:37:26 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <k0d1ta$m0c$1@smc.vnet.net>

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