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Origin of y=mx+b

  1. Feb 10, 2009 #1
    Hello, could someone please explain to me why the equation y=mx+b uses 'm' for slope and 'b' for y-intercept? This has always bothered me for some reason.
  2. jcsd
  3. Feb 10, 2009 #2


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    "m" comes from "mont", or "mount", or some french or latinized word meaning mountain, or sloping grade. The "b", I'm not sure about. Maybe (just a wild guess) base, bass, some word meaning low point, like where the "mountain" meets the "flat". I'm more certain about the "m" for "mont" as the slope.
  4. Feb 10, 2009 #3


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    The b problably comes from the fact that polynomials are typically written y=ax^n+bx^n-1+cx^n-2 etc. But the special case of a linear polynomial a=m (from what symboipoint said) and the b probably just stayed.
  5. Feb 11, 2009 #4
    In Italy, they don't use b, they use q.
  6. Feb 11, 2009 #5


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    In norway, m is called a.
  7. Feb 13, 2009 #6
    And in Britain, 'b' is called 'c'!
  8. Feb 13, 2009 #7


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    Wow, you guys have really strange alphabets!
  9. Feb 13, 2009 #8
    I always enjoyed [tex]n \cdot p_0 = n \cdot \left[ \begin{array}{c}x\\y\end{array} \right] [/tex]
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