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Cant remember how to use formula

  1. Oct 2, 2006 #1
    Cant remember how to use formula !!!

    i cant for the life of me remember which way to do this formula someone please show me the light,,,,,
    to find the slope(m) of the line you have y2 - y1 / x2 - x1 am i right then getting the result (m) you use this formula y=mx+c
    taking y1 for y and x1 for x ,
    now heres my question
    we have c = (m)(x) is it - y or is it /y

    thanks for your replys in advance..
  2. jcsd
  3. Oct 2, 2006 #2
    [tex] m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}} [/tex] [tex] y = mx+c [/tex] then [tex] c = y_1-mx_1 [/tex]
    Last edited: Oct 2, 2006
  4. Oct 2, 2006 #3
    y=mx + c is the equation of the line. Here x and y are coordinates of any point on that line.
    (y2-y1)/(x2-x2) will give you the slope m. Here x1 y1, x2 y2 are coordinates of two particular points.
    Your question makes no sense, as c is not equal to (m)(x)
  5. Oct 2, 2006 #4


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    [tex]c = -mx_{1}+y_{1}[/tex].
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