Re: Initial condition with DSolve in Mathematica 8 doesn't work

*To*: mathgroup at smc.vnet.net*Subject*: [mg116020] Re: Initial condition with DSolve in Mathematica 8 doesn't work*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Sat, 29 Jan 2011 05:27:43 -0500 (EST)

I thought the Home Version would be the same as any other, but: DSolve[{y'[x] + y[x] == a Sin[x], y[0] == 0}, y[x], x] {{y[x] -> -(1/2) a E^-x (-1 + E^x Cos[x] - E^x Sin[x])}} $Version "8.0 for Mac OS X x86 (64-bit) (November 6, 2010)" Bobby On Fri, 28 Jan 2011 05:14:21 -0600, Bert RAM Aerts <bert.ram.aerts at gmail.com> wrote: > When I enter the following in Mathematica 8.0.0 Home Edition: > DSolve[{y'[x] + y[x] == a Sin[x], y[0] == 0}, y[x], x] > I get > DSolve::deqn: Equation or list of equations expected instead of True > in the first argument {y[x]+(y^\[Prime])[x]==a Sin[x],True}. >> > > The initial condition becomes a "True"... > > In Mathematica 7.0.1 Home Edition, this same input gives the expected > output: > {{y[x] -> -(1/2) a E^-x (-1 + E^x Cos[x] - E^x Sin[x])}} > > What am I missing? > -- DrMajorBob at yahoo.com