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Linear Graphs

  1. Mar 25, 2008 #1
    The question reads: find the value of k to make the points (3,9) (7, k), and (-1,6) collinear.

    Does this involve using the distance formula? Whether or not it does, how would I go about solving this problem?
  2. jcsd
  3. Mar 25, 2008 #2


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    What does collinear mean? That means that those 3 points lie on the same straight line.
    So there are two methods you can use to find k.

    You can find the straight line equation through all the points and then sub the co-ord you want to get.

    OR you can use what you know about the slope of a line to aid you in an easier fashion.
  4. Mar 25, 2008 #3
    ok thank u!
  5. Mar 25, 2008 #4
    question 2

    write an equation for the line that contains (0, 3) and is perpendicular to the line 6x-2y=1.

    So for this question, i've found the slope of the line 6x-2y=1 which was 3. But would the slope for line (0, 3) be -1/3?
  6. Mar 26, 2008 #5


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  7. Apr 8, 2008 #6
  8. Apr 8, 2008 #7


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    Oh, dear! A "linear regression" utility to determine the equation of a line through 2 points. Do you use a calculator to add 1+ 1?

    You're just "showin' off" aren't you dexteronline?
  9. Apr 8, 2008 #8
    I could be done easier
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