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I would like to remove the remainder from a fraction if possible. I want a function

$$f(x,y) = x/y - remainder$$

for example

$$f(3,2) = 1$$ $$f(7,2) = 3$$ $$f(12,5) = 2$$

It seems so simple but its been bugging me for a while. Please help.

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What properties do you want this remainder to have? Do you want it to be an integer? Because it seems to me like you're looking at standard integer division. – Patrick Da Silva Jun 14 '13 at 12:32
Do you mean something like – Amzoti Jun 14 '13 at 12:33
x and y are both integers. The output of f(x,y) is also an integer. Yes I need something like a floor function but I want it from first principles if possible – Manatok Jun 14 '13 at 12:37
up vote 1 down vote accepted

You are looking for division with remainder We have $y=\lfloor \frac yx \rfloor x+r$, where $f(x,y)=\lfloor \frac yx \rfloor, r=y-\lfloor \frac yx \rfloor x$. What do you mean by "from first principles?"

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I want to define floor from first principles if possible. So knowing what x and y are, using basic arithmetic determine what the remainder is. – Manatok Jun 14 '13 at 13:12

Floor function will do what you want . Floor function of the value obtained by normal divison .

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