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Re: operator ^ for power
Posted: Sun Sep 27, 2015 9:45 am
by Lord
@said:
Dont' try further, it's useless. They don't want to understand.
Real mathematicians understand, others don't....
I'm out of this.
Re: operator ^ for power
Posted: Sun Sep 27, 2015 12:19 pm
by Little John
Lord wrote:You have to set correct parenthesis in order to get a correct result.
Lord wrote:-9^0.5 = i*3 is the only correct answer.
Lord wrote:Real mathematicians understand, others don't
You mean "real mathematicians" like you, who are not sure what they want to believe, and who at he same time think they know better than e.g. Wolfram Alpha?
This actually seems to apply here.
Re: operator ^ for power
Posted: Sun Sep 27, 2015 1:10 pm
by GPI
Its a funny thing. It seems that excel calculate wrong (Maybe because of compatiblity reasons).
Code: Select all
-9^2 81
(-9)^2 81
0-9^2 -81
-(9^2) -81
2^2^2^2 256
2^(2^(2^2)) 65536
(((2^2)^2)^2) 256
that 2^2^2^2 = 256 is definitiv wrong.
I found something in the wikipedia (sorry, only in German):
https://de.wikipedia.org/wiki/Un%C3%A4res_Minus
It seems, that Unary Minus is not common in the Mathematics.
https://en.wikipedia.org/wiki/Unary_operation
And:
https://en.wikipedia.org/wiki/Order_of_operations
However, some computer systems may resolve the ambiguous expression differently. For example, Microsoft Office Excel evaluates a^b^c as (a^b)^c, which is opposite of normally accepted convention of top-down order of execution for exponentiation.
edit: btw. who is brave engouth to write to MS, that Excel and for example Visual Basic calculate 2^2^2 and -2^2 complete diffrent?
Re: operator ^ for power
Posted: Sun Sep 27, 2015 1:22 pm
by Danilo
GPI wrote:edit: btw. who is brave engouth to write to MS, that Excel and for example Visual Basic calculate 2^2^2 and -2^2 complete diffrent?
For VB, it is
documented in the VB help (see Remarks). Check Excel help, it's probably also documented.
Re: operator ^ for power
Posted: Sun Sep 27, 2015 1:34 pm
by GPI
Because it is documented, it doesn't mean that it is right. In mathematics only one can be right, not both.
Re: operator ^ for power
Posted: Sun Sep 27, 2015 1:43 pm
by Danilo
GPI wrote:Because it is documented, it doesn't mean that it is right.
It could mean that MS probably already knows about it, but of course you are free to write them anyway.
Re: operator ^ for power
Posted: Sun Oct 04, 2015 4:12 pm
by Tenaja
If you are an archeologist, are you going to lecture a gardener on the proper use of a shovel? No, it would slow the gardener down. Likewise, an archeologist would not be wise to listen to a gardener, as he could damage artifacts.
Likewise, do not get too worked up about what others are doing with their shovel (or mathematical symbols) just because you use it for delicate work, and someone else just wants to get the job done asap. If you don't like they way LJ is using his shovel, then write your own!
Re: operator ^ for power
Posted: Sun Oct 04, 2015 8:22 pm
by Shield
GPI wrote:Because it is documented, it doesn't mean that it is right. In mathematics only one can be right, not both.
This only applies to concepts, not to notation.
Re: operator ^ for power
Posted: Mon Oct 05, 2015 7:59 am
by Lord
Finally:
Little John wrote:...
You mean "real mathematicians" like you, who are not sure what they want to believe, and who at he same time think they know better than e.g. Wolfram Alpha?
...
That's the center of your small universe? Sorry for that.
Little John wrote:...
This actually seems to apply here.
...
Excellent self diagnosis.
Re: operator ^ for power
Posted: Tue Oct 06, 2015 7:38 pm
by Little John
Lord wrote:Finally:
Little John wrote:...
You mean "real mathematicians" like you, who are not sure what they want to believe, and who at he same time think they know better than e.g. Wolfram Alpha?
...
That's the center of your small universe? Sorry for that.
No, it isn't. And I didn't write anything like that.
You are not even able to understand a simple sentence, or you are deliberately trying to distort its sense.
This is an impressive demonstration of how you are replacing facts with weird assumptions.
No further comment required.
Re: operator ^ for power
Posted: Tue Oct 06, 2015 8:55 pm
by GPI
Lord wrote:Excellent self diagnosis.
At the beginning, I also thought, that Little John was wrong.
It is always a good Idea to keep in Mind, that maybe it is wrong. In this case I try to find information in the Internet about this things. I found only sources, that -2^9 is equal to -(2^9). Only Excel (and Open/Libre Office - I think because of compatiblity reasons) calculates diffrent. But Excel handle the power-Operator in other cases also complete false (yes it is documentet, but that doesn't change anything).
And there are Mathematic Rules. For Example: 2+2*2 = 6 and not 8.
But you don't do something like this: You don't search for Answers. I asked you to link any sources, that you are right.