Re: Re: Simplifying ArcTan
- To: mathgroup at smc.vnet.net
- Subject: [mg55554] Re: [mg55541] Re: [mg55526] Simplifying ArcTan
- From: "David Park" <djmp at earthlink.net>
- Date: Tue, 29 Mar 2005 03:42:37 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I don't know what I was thinking! It should be without the condition on x.
But why shouldn't
FullSimplify[ArcTan[Cos[x], Sin[x]],
-Pi < x <= Pi]
simplify to x? After all, the two argument ArcTan works for all combinations
of arguments, except ArcTan[0, 0] and even that gives Interval[{-Pi, Pi}].
ArcTan[0, 3]
Pi/2
In fact, why shouldn't it simplify to x just by specifying that x is Real?
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: Florian Jaccard [mailto:florian.jaccard at he-arc.ch]
To: mathgroup at smc.vnet.net
It does !
But you have to avoid 2 mistakes :
1) The brackets on wrong place
2) x may not be Pi/2
In[4]:=
FullSimplify[ArcTan[Cos[x], Sin[x]],
x >= 0 && x < Pi/2]
Out[4]=
x
-----Message d'origine-----
De : fizzy [mailto:fizzycist at knology.net]
Envoyé : lun., 28. mars 2005 09:42
À : mathgroup at smc.vnet.net
Objet : [mg55526] Simplifying ArcTan
Why does FullSimplify[ ArcTan[ Cos[x], Sin[x] , x>=0 && x <= Pi/2 ]
not output x ?
Thanks...jerry blimbaum