Re: Bug of Integrate
- To: mathgroup at smc.vnet.net
- Subject: [mg82722] Re: Bug of Integrate
- From: Costa Bravo <laguna at aol.com>
- Date: Tue, 30 Oct 2007 03:19:24 -0500 (EST)
- References: <fg4dfv$6c3$1@smc.vnet.net>
Miguel wrote:
> Integrate[Sqrt[1/Cos[t]^2]*3*Cos[t],{t,0,2Pi}] Mathematica 6.0.1
> yields -6*Pi.
this is bug
Mathematica 5.0 yields 0 (OK !)
>
> Simplifying the expresion resultrs Integrate[3,{t,0,2*Pi}]
No
Assuming[t>0,Sqrt[1/Cos[t]^2]*3*Cos[t]//Simplify]
Out : 3 Abs[Sec[t]] Cos[t] (* w *)
=> w = If[ 1/2Pi < t < 3/2Pi, -3, 3 ]
--
Costa