EKS Posted January 30, 2010 Share Posted January 30, 2010 Problem 1-3 number 40 if you have the text. The problem is to simplify the following expression: x-[x-(x-x-y) however, the x-y part at the end has a line over the top of it. What does the line over the top mean? Quote Link to comment Share on other sites More sharing options...
kiana Posted January 30, 2010 Share Posted January 30, 2010 Hmm, in older mathematical notation a line over the top would signify the same as parentheses -- this is actually the reason that the line over the radical symbol extends over everything inside the radical, iirc. It would also make sense in this context, as the student would need to repeatedly distribute the negative sign. In some parts of math, a line over the top sometimes indicates a vector or a complex conjugate, but neither of those seems to fit the given problem...so I'd go with the parentheses. Does that fit the answer key? If this isn't what they mean, then I have no idea. :D Quote Link to comment Share on other sites More sharing options...
Kathy in Richmond Posted January 30, 2010 Share Posted January 30, 2010 It's an old-fashioned grouping symbol, used in the same manner as parentheses and brackets. You can rewrite this expression as x - [ x - ( x - { x - y } ) ] Btw, Foerster mentions this symbol on page 14 in Note #2. hth, ~Kathy Quote Link to comment Share on other sites More sharing options...
EKS Posted January 30, 2010 Author Share Posted January 30, 2010 Yes--it fits the answer key. As for the note on page 14--it would help if I were to actually *read* the lesson before cranking out the problems!:D Quote Link to comment Share on other sites More sharing options...
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