Re: nasty integrals that Mathematica can't do
- To: mathgroup@smc.vnet.net
- Subject: [mg10826] Re: nasty integrals that Mathematica can't do
- From: Allan Hayes <hay@haystack.demon.co.uk>
- Date: Tue, 10 Feb 1998 21:01:39 -0500
- References: <6baoqa$cdu@smc.vnet.net>
> In my research, i've come up with the following integral: > > Integrate[ CosIntegral[a x] Cos[b x], {x,0,Infinity} ] > > Gradshteyn and Ryzhik have this integral, but apparently, Mathematica > 3.0.1 can't do it. > > My question: Is there a way to "teach" Mathematica how to do a > particular type of integral? Can I somehow plug G+R's solution in > Mathematica? Pete, You can certaily plug in the solution: Unprotect[Integrate]; Integrate[ CosIntegral[a_ x] Cos[b_ x], {x,0,Infinity} ]:= GR[a,b] Protect[Integrate]; Now we get Integrate[ CosIntegral[5 x] Cos[7 x], {x,0,Infinity} ] GR[5, 7] -- Allan Hayes Training and Consulting Leicester, UK hay@haystack.demon.co.uk http://www.haystack.demon.co.uk voice: +44 (0)116 271 4198 fax: +44 (0)116 271 8642