Question

what does x bar mean in calculus?
for example at
http://tutorial.math.lamar.edu/Classes/CalcII/SeriesCompTest.aspx
in Limit Comparison Test (at the end of the page) it has c bar, should I consider it as a mean (avg)?

Answer 1

not seeing a bar.

Answer 2

can you do a screenshot and mark it in Paint?

Answer 3

yeah sure plzz wait

Answer 4

maybe I am calling it wrong

Answer 5

they just defined \[\bar c=\frac{1}{c}\]

Answer 6

yes, the line to the left of the arrow has c on the left and 1/c_bar on the very right.

reciprocal.

Answer 7

but on http://en.wikipedia.org/wiki/List_of_mathematical_symbols it says that it's mean, if it's not definded that whether it's a reciprocal or not then how would we determine that it's a mean or reciprocal likewise in this case it has been told that it's a reciprocal therefore we know it

Answer 8

When you write a proof, you can define symbols to mean anything you like. And here they did. The bar is sometimes used for the complement, sometimes for the mean, sometimes for the reciprocal, and sometimes something else entirely.

I could write a paper and define the bar to mean "squared" if I wanted.

Answer 9

got it

Answer 10

thanks

Answer 11

(and complex conjugate, and algrebraic and topological closure :-)