Re: integration problem
- To: mathgroup at smc.vnet.net
- Subject: [mg16264] Re: integration problem
- From: James Escamilla <jescamilla at ti.com>
- Date: Fri, 5 Mar 1999 00:41:25 -0500
- Organization: Texas Instruments
- References: <7bg12h$5kf@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Michel Gosse wrote:
>
> Hello
> Mathematica 3.01 returns infinity for the calculus :
> Integrate[1/(2*x + Sqrt[3*x + 1]), {x, 0, 1}]
> but when i evaluate :
> NIntegrate[1/(2*x + Sqrt[3*x + 1]), {x, 0, 1}]
> it returns 0.449, which seems good.
> What is the problem with the integrate function ?
> Regards
My calculator (a TI-89) returns LN(256/27)/5 for
Integrate[1/(2*x + Sqrt[3*x + 1]), {x, 0, 1}].
It also solves Integrate[1/(2*x + Sqrt[3*x + 1]), x] as:
-LN((ABS(2*SQRT(3*X+1)-1))^3/(243*(ABS(SQRT(3*X+1)+2))^3*
(ABS(SQRT(3*X+1)+2*X))^5))/10
If Mathematica can't solve this and my calculator can,
I'd say it's a BIG BUG in Mathematica.