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
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