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Ahhh guys, is d/dxf(x)=f'(x)?

  1. Nov 19, 2012 #1
    ahhh guys, is d/dxf(x)=f'(x)??????

    I just don't get it, my classmates are finding the deravative of f(x), i'd think that d/dx(f(x))=f'(f(x))=some annoying long equations...

    but they get d/dx(f(x))=f'(x)??? am I doing a silly mistake here?
  2. jcsd
  3. Nov 19, 2012 #2


    Staff: Mentor

    Re: ahhh guys, is d/dxf(x)=f'(x)??????

    Your classmates are right. Your mistake seems to be in thinking that d/dx is the same as f'. It's not. d/dx is an operator that works on a function; f' already is a function.

    ## \frac{df(x)}{dx}## and f'(x) are essentially two different notations for the same thing.
  4. Nov 19, 2012 #3
    Re: ahhh guys, is d/dxf(x)=f'(x)??????

    damn I'm stupid... well thanks a LOT. It's 1 am but who needs sleep!!!! go homework&euroshopper energy drink
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