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Re: Output display of exponential function in Mathematica

The output that you want is "unstable", i.e., Mathematica automatically 
converts it.

25*5^h

5^(h + 2)

You will have to force the form

sr=n_Integer^(m_Integer+x_):>HoldForm[Evaluate[n^m]]*n^x;

5^(2+h)/.sr

5^h*HoldForm[25]

ReleaseHold[%]

5^(h + 2)

expr=5^(7x/2)-5^(x^2);

Sqrt[5^x]*Simplify[expr/Sqrt[5^x],
    Element[x, Reals]]

Sqrt[5^x]*(-5^(x^2 - x/2) + 125^x)


Bob Hanlon

> 
> From: Bookreader <Bookreader127@yahoo.com>
> Date: 2005/11/26 Sat AM 02:47:04 EST
> Subject:  Output display of exponential function in Mathematica
> 
> How can I get Mathematica to display 25(5^h) when I input 5^(2+h)?
> 
> Also, is there a way to solve this question?  I've read the help.  I'm
> studying for my final and am trying to find the answer to an
> even-numbered question from my text.
> 
> Factor 5^(7x/2) - 5^(x^2), with sqrt(5^x) being one of the factors.
> The answer I get is sqrt(5^x) times( (5^7)-1).
> 
> Thanks for showing me how to do these.
> 
> 

0
hanlonr (2279)
11/27/2005 8:24:53 AM
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On Sun, 27 Nov 2005 08:24:53 +0000 (UTC), Bob Hanlon <hanlonr@cox.net>
wrote:

>The output that you want is "unstable", i.e., Mathematica automatically 
>converts it.
>

Thanks.

I have another question if you don't mind.

I'm trying to just check and see if I got a whole bunch of
even-numbered study exercises right on exponents and natural logs.
The answers to the odds are in the book.

As an example, LN(1/e^2) equals what?

My answer is -1/2.

In mathematica, I tried Simplify[LN(1/e^2)] and it just spit the same
thing out as the output.  I also tried a couple of variations of
Solve[LN[1/e^2] = X] with essentially the same result

How would you get Mathematica to verify that the answer is -1/2.

Thanks a lot.

0
NewGuy1 (34)
12/1/2005 4:58:48 AM
New Guy wrote:
> I'm trying to just check and see if I got a whole bunch of
> even-numbered study exercises right on exponents and natural logs.
> The answers to the odds are in the book.
> 
> As an example, LN(1/e^2) equals what?
> 
> My answer is -1/2.
> 
> In mathematica, I tried Simplify[LN(1/e^2)] and it just spit the same
> thing out as the output.  I also tried a couple of variations of
> Solve[LN[1/e^2] = X] with essentially the same result
> 
> How would you get Mathematica to verify that the answer is -1/2.

Use the correct syntax :-) The natural logarithm of the number a, say, 
is written Log[a]. Check

http://documents.wolfram.com/mathematica/functions/Log

Now, the base of the natural logarithm is written E (capital e). 
Therefore, you can check your answer with

In[1]:=
Log[1/E^2]

Out[1]=
-2

(Hint: Log[1/E^2] <==> Log[1] - Log[E^2]...)

Hope this helps,
/J.M.

0
12/2/2005 11:05:41 AM
New Guy schrieb:
> On Sun, 27 Nov 2005 08:24:53 +0000 (UTC), Bob Hanlon <hanlonr@cox.net>
> wrote:
> 
>> The output that you want is "unstable", i.e., Mathematica automatically 
>> converts it.
>>
> 
> Thanks.
> 
> I have another question if you don't mind.
> 
> I'm trying to just check and see if I got a whole bunch of
> even-numbered study exercises right on exponents and natural logs.
> The answers to the odds are in the book.
> 
> As an example, LN(1/e^2) equals what?
> 
> My answer is -1/2.
> 
> In mathematica, I tried Simplify[LN(1/e^2)] and it just spit the same
> thing out as the output.  I also tried a couple of variations of
> Solve[LN[1/e^2] = X] with essentially the same result
> 
> How would you get Mathematica to verify that the answer is -1/2.
> 
> Thanks a lot.
> 
Hi,

I really hope, Mathematica does not, because 1/(E^2) equals 
(E^2)^(-1)==E^(-2) and therefore the Log[1/E^2] is -2 (use "E" for the 
base of the natural logarithm instead of "e").

Peter

0
petsie (836)
12/2/2005 11:16:20 AM
On Fri, 2 Dec 2005 11:05:41 +0000 (UTC), Jean-Marc Gulliet
<jeanmarc.gulliet@gmail.com> wrote:

>Use the correct syntax :-) The natural logarithm of the number a, say, 
>is written Log[a]. Check
>

Agreed.  Back and forth I go because in class and with our instructor
it's LN.  Sorry for the inconvenience.

>Now, the base of the natural logarithm is written E (capital e). 

Beg to differ here.  The BasicInput.nb palette uses the small 'e' that
is kind of double-struck.

Bookreader

0
NewGuy1 (34)
12/4/2005 10:58:05 AM
Reply: