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up vote -1 down vote favorite

$\frac{e^{0.75}}{-0.5^e+10000}$

This doesn't work either:

$\frac{2.72^{0.75}}{-0.5^{2.72}+10000}$

I can even solve it with a calculator.

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2  
I don't understand the problem. Did you look up how to correctly enter mathematical expressions in those programs? How did you try to enter them? – Jonas Meyer Jun 5 '12 at 11:13
(e^0.75)/((-0.5)^e+10000) – Friend of Kim Jun 5 '12 at 11:19
And with 2.72 instead of e – Friend of Kim Jun 5 '12 at 11:19
screencast.com/t/OBW9dbURsXF screencast.com/t/Sv3ZzWKJYJMy A = the intersection between a and g. – Friend of Kim Jun 5 '12 at 11:22

2 Answers

up vote 4 down vote accepted

First of all, $(-0.5)^e$ is not the same as $-0.5^e$.

Secondly, $x^y$ is not well defined (at least not as a real number) if $x < 0$ and $y$ is not an integer.

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I know that there is a difference between (−0.5)^e and −0.5^e, none of them worked. So you are saying that they cannot solve it because of their scripts, not because the math is not supposed to work? – Friend of Kim Jun 5 '12 at 11:39
3  
@50ndr33 From your reply in the comment above, you seemed confused about the difference. (You wrote one thing in the question, another in the comment.) I don't have any of the two programs you mention available, but I know there are some programs that get the priority rules wrong, i.e. interpreting $-0.5^e$ as $(-0.5)^e$. Wolfram Alpha gets it right: wolframalpha.com/input/?i=e%5E0.75%2F%28-0.5%5Ee%2B10000%29 – mrf Jun 5 '12 at 11:52
up vote 1 down vote

Mathway refuses to numerically evaluate. Geogebra Does evaluate the expression correctly

e^(.75)/(10000-.5^e)

Gives 

a=0

but if you right click on a and go to object properties the value says 

0.00021

which agrees with google calculator

https://www.google.com/search?q=exp%28.75%29%2F%2810000-.5^e%29

Why you would want to evaluate this in geogebra is beyond me

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Why you would want to evaluate this in geogebra is beyond me: It was because I wanted to draw this as a graph. But it said undefined with values of 1 or less on the x-axis. (0.5 = x) – Friend of Kim Jun 5 '12 at 13:47
Then as others have stated before me the expression you typed and what you are asking geogebra to evaluate are not the same thing $-.5^e \neq (-.5)^e$. The expression $(-.5)^e$ isn't even well defined. – Nate Iverson Jun 5 '12 at 15:48
So the expression $x^e$ is only a well defined real number if $x \ge 0$. Your calculator may be giving you one of the possible complex multi-valued solutions. – Nate Iverson Jun 5 '12 at 15:49

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