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Re: Replacement Rule with Sqrt in denominator

• To: mathgroup at smc.vnet.net
• Subject: [mg114337] Re: Replacement Rule with Sqrt in denominator
• From: Bill Rowe <readnews at sbcglobal.net>
• Date: Wed, 1 Dec 2010 02:13:15 -0500 (EST)

On 11/20/2010 3:11 AM, kj wrote:

>I don't know a way to write the replacement rule so that it works
>for both Sqrt[x] and 1/Sqrt[x], but maybe someone else does.

This is easy using Alternatives. For example:

In[2]:= a Sqrt[x] /. Sqrt[x] | Power[x, _] -> b

Out[2]= a b

In[3]:= a/Sqrt[x] /. Sqrt[x] | Power[x, _] -> b

Out[3]= a b

Note, I've only shown a simple way to solve the specific issue.
I did not make the alternative using Power sufficiently
restrictive to prevent say x^2 from being replaced by b. If
there is to be made to cover the possibility of that something
like x^2 will be present but should not be replaced, the
alternative using Power would need to be more specific.