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Homework Help: What does the . in equations stand for?

  1. Mar 22, 2008 #1
    What does the "." in equations stand for?

    I've been revising electric fields, and have come across the equation [tex] \Delta E_{p} = k . Q_{1} Q_{2} [ \frac{1}{r_{1}} - \frac{1}{r_{2}}] [/tex]

    I have never come accross a decimal point in an equation before, what does it mean?
    Last edited: Mar 22, 2008
  2. jcsd
  3. Mar 22, 2008 #2


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    Homework Helper

    "." is another way of saying "multiplied by"
  4. Mar 23, 2008 #3


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    It is to avoid using [itex]\times[/itex] which can be used to represent a variable. It would cause confusion hence a dot is used to show multiplication.
  5. Mar 23, 2008 #4


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    Note, it's not a period, as in [ilatex]a . b[/ilatex], it's a midline-dot, like [ilatex]a \cdot b[/ilatex]

    - Warren
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