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What does backslash dot mean as a command?

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Clash Royale CLAN TAG #URR8PPP .everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty margin-bottom:0; up vote 11 down vote favorite 2 A software I installed inserted a line in my profile that reads: [ -s "$SOME_FILE" ] && . "$SOME_FILE" I know dot . is synonymous with source , so I suspect this is just sourcing the file, but I have never seen . before; does it do something else? Edit, regarding DVs: searching for "backslash dot" leads to questions regarding ./ when calling executable files, and man source leads to a manpage where . does not appear. I don't know what else to try, hence the question. Edit 2: see related questions Why start a shell command with a backslash Backslash at the beginning of a command Why do backslashes prevent alias expansion Run a command that is shadowed by an alias bash share | improve this question edited 22 hours ago psmears 433 2 8 asked yesterday...

Derivative to function ratio

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Clash Royale CLAN TAG #URR8PPP up vote 1 down vote favorite 1 Is there a physical meaning for derivative of the function to function ratio? That is, this quantity, $$ Q(x) = frac1f(x)fracdf(x)dx $$ Like for instance, if $f$ is the potential energy, this would be work to potential energy ratio. Or even what can we say about $Q(x)$, say when $Q(x)<0$. derivatives share | cite | improve this question asked 16 hours ago user2167741 97 9 This is the scaling factor of the derivitive to the function. This quantity gives an intuition of how the function relates to its gradient. – Nick 15 hours ago 1 I also learned that this is called 'logarithmic derivative'. en.wikipedia.org/wiki/Logarithmic_derivative – user2167741 15 hours ago add a comment  |  up vote 1 down vote favorite 1 Is there a physical meaning for derivative of the f...