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Math question

**bylaardt**:

-2² = ?

I know! obvious "-4", but :

--- Code: Pascal [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} ---Symbolic.QuickEvaluate('-2^2',[],[]))returns 4

Other expressions parsers based on rpn conversion, return "4" too.

spreedshets like Libreoffice, GoogleSheets (https://www.google.com/sheets/about/) retur "4"

is this a collective bug or a expected behavior?

PS: 0-2^2 returns "-4" as expected.

**howardpc**:

It is a question of interpretation.

Does -2² mean (-2)*(-2) or -(2²)?

Mathematician's conventions may differ from programmers or writers of scripting languages.

**wp**:

See the section on "Exceptions" in https://en.wikipedia.org/wiki/Order_of_operations

Use parenthesis for clarification: (-2)^2 = 4 or -(2^2) = -4

**taazz**:

--- Quote from: bylaardt on February 23, 2016, 07:18:23 pm ----2² = ?

is this a collective bug or a expected behavior?

--- End quote ---

Any negative multiple by a negative number it will yield a positive number. It is basic multiplication theory http://www.mathsisfun.com/multiplying-negatives.html

**taazz**:

--- Quote from: howardpc on February 23, 2016, 07:29:29 pm ---It is a question of interpretation.

Does -2² mean (-2)*(-2) or -(2²)?

Mathematician's conventions may differ from programmers or writers of scripting languages.

--- End quote ---

no its not, if there is no parenthesis specified then your first interpretation is implied.

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