Re: automatic integral output simplification

*To*: mathgroup at smc.vnet.net*Subject*: [mg115191] Re: automatic integral output simplification*From*: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>*Date*: Tue, 4 Jan 2011 04:23:08 -0500 (EST)*References*: <ifs310$opc$1@smc.vnet.net>

In[121]:= Integrate[-8 Sin[2 t], {t, 0, t}] // TrigReduce Out[121]= 4 (-1 + Cos[2 t]) Cheers -- Sjoerd On Jan 3, 9:57 am, sean k <seaninso... at gmail.com> wrote: > Hello group, > > I want to get around the way Mathematica simplifies the output of an > integral. > > For instance, Let's say you want to integrate -8 sin(2t) from t = {0, > t} > > int1 = \[Integral]-8 Sin[2 t] \[DifferentialD]t > ul1 = int1; > ll1 = int1 /. t -> 0; > ul1 - ll1 > > yields the correct output. > > -4 + 4 Cos[2 t] > > But if i pose that integral with limits included in it, Mathematica > outputs > > Integrate[-8 Sin[2 t], {t, 0, t}] > > -8 Sin[t]^2 > > Now both these are correct, except when the definite integral is > evaluated, "mathematicamagic" kicks in. > > My guess is that the coefficient in the argument for the sin function > is the culprit. What should I do here to make the Mathematica retain > the "2 t" inside the Sin? > > Thanks in advance for any insights. > > Sean