       Re: Forcing functions

• To: mathgroup at smc.vnet.net
• Subject: [mg51027] Re: [mg51006] Forcing functions
• From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
• Date: Sat, 2 Oct 2004 03:17:55 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

```On 1 Oct 2004, at 17:48, Barry Tesman wrote:

> Can you "force" Mathematica to not use certain functions?  E.g., I
> want to give my students some problems to antidifferentiate.  One
> such problem is:
>
> Integrate[ x * Sqrt[x^2 + 2x +4], x]
>
> The answer uses arcsinh.  Can one force Mathematica to use natural
>
> Thanks,
> Barry
>
The answer is not really , but....

If you evaluate at the begining of a session:

\$Post = (If[! FreeQ[#, ArcSinh | ArcCosh], TrigToExp[#], #] &);

then

Integrate[x*Sqrt[x^2+2x+4],x]

(1/6)*(Sqrt[x^2 + 2*x + 4]*(2*x^2 + x + 5) - 9*Log[(x + 1)/Sqrt +
Sqrt[(1/3)*(x + 1)^2 + 1]])

You could even put this definiton into an init.m file so that it is
evaluated every time Mathematica is run.

Andrzej Kozlowski
Chiba, Japan
http://www.akikoz.net/~andrzej/
http://www.mimuw.edu.pl/~akoz/

```

• Prev by Date: Re: Fast multiplication of polynomials mod p
• Next by Date: Re: Suggestion to WRI for notebook navigation (frontend)
• Previous by thread: Re: Forcing functions
• Next by thread: Re: Forcing functions