       Re: SameQ to check for simplified radical expressions... doesn't work

• To: mathgroup at smc.vnet.net
• Subject: [mg120988] Re: SameQ to check for simplified radical expressions... doesn't work
• From: Heike Gramberg <heike.gramberg at gmail.com>
• Date: Sat, 20 Aug 2011 06:18:09 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201108191033.GAA23940@smc.vnet.net>

```Maybe you can convert your expressions to strings and use StringMatchQ. For example

StringMatchQ[ToString[Sqrt], ToString[HoldForm[6 Sqrt]]]

returns True, and

StringMatchQ[ToString[Sqrt], ToString[HoldForm[Sqrt]]]

returns False.

Note that Simplify isn't needed since Mathematica automatically
reduces square roots to their simplest radical form.

Heike.

On 19 Aug 2011, at 12:33, Roy Simpson wrote:

> Hello,
>
> I have what appears to be a simple issue, but I cannot for the life of me figure it out.  I will have a randomized number, a, and I am going to simplify the square root of this.  Then I want to compare this to a radical expression that a student enters, say b.  Thus, the idea should be something like
>
> Simplify[Sqrt[a]] === Sqrt[b]
>
> For sake of this example, let's suppose the number I want to consider is the square root of 360.  I only want the statement to return TRUE if the rhs of this SameQ is exactly 6*Sqrt.
>
> Unfortunately,
>
> Simplify[Sqrt] === Sqrt
> returns TRUE.
>
> I tried a few variations with Hold, but they always return false if the student enters the correct answer.  For example, if the student entered 6*Sqrt, then
>
> Simplify[Sqrt] === Hold[6*Sqrt]
> returns FALSE
>
> What am I doing wrong?  Any help would be appreciated.
>

```

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