Known bug in Excel????

[mortgageman]

According to math rules 2^3^2 should equal 2^9 (you go right to left in this case). Excel gives 64. Is this a known bug?

Gene Klein

 

[Kenneth Hobson]

Yes, I thought it odd that Microsoft was not consistent in their order or operations.

The "-4" as a result for "-2^2" is the correct answer by math rules. As you can see, several programs have their own rules as we have discussed.

 

[Hap]

Agree with Hobson.
-2^2 = -4
(-2)^2 = 4

 

[mikerickson]

-2 is a number. The "-" is not an operator, its a negative flag.

There is only one operation (expotention) in the formula -2^2

 

[ZVI]

Gene, please read what is Software bug

And then please take a look on what is declared for The order in which Excel performs operations in formulas (the same as Kenneth has provided)
Citation: Excel calculates the formula from left to right, according to a specific order for each operator in the formula… If you combine several operators in a single formula, Excel performs the operations in the order shown in the following table … If a formula contains operators with the same precedence - for example, if a formula contains both a multiplication and division operator - Excel evaluates the operators from left to right

The declared functionality is not a bug.
Excel follows the declared rules therefore it’s not a bug.

BTW, the result of 4 for =-2^2 is also meet the Excel precedence rules and explained here Formula Returns Unexpected Positive Value

Vladimir
P.S. Math problems? Call 1-800-2+3x4-2^3^4

 

[Hap]

Mike. How would you know this sematically without encapsulating the "-" or assigning the negative to the 2 prior to the exponential operation?

 

[ZVI]

Mike. How would you know this sematically without encapsulating the "-" or assigning the negative to the 2 prior to the exponential operation?

In the link it is declared that:

Operator precedence
Operator Description
   :      colon         Reference operators
   ,      comma         Reference operators
          single space  Reference operators
   –      Negation (as in –1)
   %      Percent
   ^      Exponentiation
* and /   Multiplication and division
+ and –   Addition and subtraction
   &      Connects two strings of text (concatenation)
=  <  >  <=  >=  <> Comparison

 

[Colin Legg]

I don't think Excel can handle Reverse Polish Notation.

Incidentally, Excel parses its formulae using modified Reverse Polish Notation.

In the link it is declared that:

Exactly, negation takes precedence over exponentiation in Excel formulae.

 

[FastExcel]

I like reverse polish notation in the HP48SX. In the context of this thread, I used HP48SX and HP48GX in scientific and equation modes.

Here is a summary of my tests:

My version of vb.net gives 64 for Msgbox 2^3^2

 

[Hap]

There exist differing conventions concerning the unary operator − (usually read "minus"). In written or printed mathematics, the expression −32 is interpreted to mean −(32) = −9,[citation needed] but in some applications and programming languages, notably the application Microsoft Office Excel and the programming language bc, unary operators have a higher priority than binary operators, that is, the unary minus (negation) has higher precedence than exponentiation, so in those languages −32 will be interpreted as (−3)2 = 9. [1]. In any case where there is a possibility that the notation might be misinterpreted, it is advisable to use brackets to clarify which interpretation is intended.

As Quoted From Wikipedia

 

[Norie]

Hap

-(32) = -9?

Is there an operator missing there?