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Re: 1/Trig function - help

• To: mathgroup at smc.vnet.net
• Subject: [mg24261] Re: [mg24248] 1/Trig function - help
• From: Andrzej Kozlowski <andrzej at tuins.ac.jp>
• Date: Wed, 5 Jul 2000 23:10:41 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

Here is one simple way which may perhaps be satisfactory:

In[11]:=
Unprotect[Csc, Sec];
In[12]:=
Format[Csc[x_]] := 1/sin[x];
In[13]:=
Format[Sec[x_]] := 1/cos[x];
In[14]:=
Protect[Csc, Sec];


Now,  for example:
In[15]:=
D[Tan[x], x]
Out[15]=
   1    2
(------)
 cos[x]

You can still to comutations in the usual way:

In[16]:=
% /. x -> 0
Out[16]=
1

Andrzej
-- 
Andrzej Kozlowski
Toyama International University, JAPAN

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on 7/5/00 4:22 AM, zhl67 at my-deja.com at zhl67 at my-deja.com wrote:

> Hello,
> 
> For some reason I wish the trigonometric functions to the power of -1
> not automatically evaluated to some other trig functions. For instance,
> I wish the out put of
> 
> In[1]:= Sin[x]^(-1)
> 
> remain unchanged or appears as
> 
> 1
> Out[1]:=-------
> Sin[x]
> 
> but NOT Csc[x]. Is there any cost efficient way to do this? Adding
> rules to Power function might do(I only wish this feature for certain
> argumentx x), but it slows down the Power function at the same time.
> 
> Liu Zhao
> 
> 
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>