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Re: Surface Normal

• To: mathgroup at smc.vnet.net
• Subject: [mg55193] Re: Surface Normal
• From: "Carl K. Woll" <carlw at u.washington.edu>
• Date: Wed, 16 Mar 2005 05:36:15 -0500 (EST)
• Organization: University of Washington
• References: <d15s2g$9k2$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

<gouqizi.lvcha at gmail.com> wrote in message news:d15s2g$9k2$1 at smc.vnet.net...
> Hi, All:
>
> If I have a surface in parametric form
>
> For example,
> x = (10 + 5cosv)cosu
> y = (10 + 5cosv)sinu
> z = 5sinv
>
> How can I quickly calculate its normal for any (u,v) by mathematica
>
> Rick
>

Rick,

What about the following

Cross[ D[ {x,y,z}, u], D[ {x,y,z}, v] ]

Carl Woll