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Basic calculus notation help.

  1. Feb 4, 2012 #1
    It's been a while since I've done calculus and now a simple derivative is stumping me.

    This is the issue: d(xf)/dx= ?

    This is just the product rule, so I think: x(df/dx) + f (dx/dx)= x (df/dx) + f

    But I'm afraid that I don't even understand my own notation anymore (how embarrassing)...

    if I had a derivative like x (d/dx), would this just be the derivative of x, i.e. 1? So what does x df/dx mean? You can't simplify that anymore, right? Maybe I just need to go reread my calc 1 textbook..
  2. jcsd
  3. Feb 4, 2012 #2
    No, that is x multiplied by the derivative of f, you cannot simplify more.
  4. Feb 4, 2012 #3
    x df/dx is the derivative of the function, f, with respect to, x, multiplied by x
  5. Feb 4, 2012 #4
    Is d(xf)/dx= x(df/dx) + f (dx/dx)= x (df/dx) + f ?

    This was your original question. The answer is yes.
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