Solving Mistake in my Book: (b-a)^2/12

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The discussion centers on a mathematical expression involving the equation (b-a)^2/12 and its derivation from (1/3)(b^2+ab+a^2)-(1/4)(b^2+2ab+a^2). Participants identify a potential error regarding an unexplained multiplication by 2 in the intermediate step shown as (b^2-2ab+a^2)/12. Clarification is sought on whether this multiplication is a typographical error, as it is not documented in the errata. Ultimately, it is agreed that the multiplication is indeed a mistake, and the participants decide to move on from the issue. The conversation highlights the importance of accuracy in mathematical texts and the need for clear errata.
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(1/3)(b^2+ab+a^2)-(1/4)(b^2+2ab+a^2)

= (b-a)^2
--------
12


I am ok with this but there is am intermediate step shown


(b^2-2ab+a^2)
-------------- (2)
12

I don't see where the multiplication by 2 comes from and it is not shown in the errata.
 
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montoyas7940 said:
(1/3)(b^2+ab+a^2)-(1/4)(b^2+2ab+a^2)

= (b-a)^2
--------
12


I am ok with this but there is am intermediate step shown


(b^2-2ab+a^2)
-------------- (2)
12

I don't see where the multiplication by 2 comes from and it is not shown in the errata.



You are right that there should be no multiplication by two there.

I am not sure how it exactly appears in your book, but does it appear like you typed it here, with the 2 between parentheses? I am asking because sometimes books number equations and often when equations are numbered, the number is put between parentheses.
 
:smile:
 
It is clearly a multiplication. It is a solution manual for a text and I can't find a published errata. I am just going to assume it is a mistake and move on. Thank you, kdv.
 
montoyas7940 said:
It is clearly a multiplication. It is a solution manual for a text and I can't find a published errata. I am just going to assume it is a mistake and move on. Thank you, kdv.

Ok. Then it is a typo.

You are welcome.
 

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