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Do you use two lines (of ruled paper) for a rational functio

  1. Aug 9, 2015 #1
    Do you use two lines (of regular ruled paper) for a rational function?

    FOr example, would you use two lines or one for the equation

    ## f(x) = (x^2-3) / x+2 ##

    I can see three ways (in general) of writing this.
    1) numerator and denominator each get one line
    2) num and den are written smaller so they both fit on one line. or.
    3) write it like latex, using the back slash

    im just asking wrt what you think looks the neatest for homework and notes.
    thank you
  2. jcsd
  3. Aug 9, 2015 #2


    Staff: Mentor

    You're missing a pair of parentheses here around the terms in the denominator. It should be ## f(x) = (x^2-3) / (x+2) ##. Otherwise, what you have written is the same as ## f(x) = \frac{x^2-3} x + 2 ##
    If you write with a fine pen/pencil, you can fit both num and den on a single line, and it's still legible. As long as it can be easily read, I don't think it makes much difference.

    If you write it like LaTeX, you don't use the slash at all - here's the LaTeX for your rational expression: \frac{x^2 - 3}{x + 2}
    In rendered form, this becomes
    $$\frac{x^2 - 3}{x + 2}$$
  4. Aug 9, 2015 #3


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    Staff: Mentor

    Line rules?
    One - that formula is short, it should fit in and does not break the layout.

    Didn't use that type of paper for years, however. Squared paper is more practical.
  5. Aug 9, 2015 #4


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    I am throwing away all assumptions, ignoring what the other posters have said, and ask: jayquestions, what are you asking? Exactly what is your function f(x)? Do you want to make a graph of your f(x)?
  6. Aug 10, 2015 #5
    I'd go with two lines. I can't stand when people try to squeeze small, illegible numbers in between lines. Makes me cringe.
  7. Aug 10, 2015 #6


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    I understand now.
    Use cartesian graph paper. Two number lines meeting at right angles.

    NO. I misunderstood here. Better answer in a following post...
    Last edited: Aug 10, 2015
  8. Aug 10, 2015 #7
    Yes I was asking about how to write legible with many equations.
  9. Aug 10, 2015 #8


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    Your question is not about graph paper, and not about what kind of paper on which to write, and not about drawing anything. Your question is really about how to handle algebraic, arithmetic, mathematical notation. Use what you are formally taught in school, for when you both study and use arithmetic and algebra.

    You show a numerator and denominator of a fraction ON PAPER (and chalkboard and dry erase board) using a horizontal bar; NOT a slash mark; to separate the numerator from the denominator. How you choose the size on paper depends on what is needed for both YOU and YOUR READER to be able to read and understand what is written.

    Forward-Slash is strictly for writing in pure text, and you usually must supply parentheses to clarify what you want to express; otherwise you either are being ambiguous or are expressing something with a different meaning.
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