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Homework Help: Slope and Special Lines

  1. Nov 2, 2005 #1
    Write an equation of a line with a slope of 0 and passing through the point (5,4).

    Write an equation of a line with an undefined slope and passing through the point (-2,4).


    I know how to do this type of thing but these two questions have stumped me.

    If the slope of the first one is zero, it'll be a horizontal line. That means the equation will look something like this: y= some number right?

    If so, what do I do with the (5, 4)? Do I just graph that point and see where it is as far as y goes? If that's what I'm to do...*Looks at a graph* y= 4? Now that I think about it, I didn't need the graph so that either means it's really easy or really wrong.:rofl:

    As for the second one, if the slope is undefined it would be vertical and would look like this: x= some number. Would it be the same way, again, assuming I did the first one right? x= -2?

    EDIT: Write an equation of a line that passes through (9,-5) and (3,-5).

    The slope is 0/-6, right? Does that make it undefined or 0? I can't tell the difference. What if the answer was -6/0? Which would that be?

    As for writing the equation, it would be x or y, whichever it is according to whether it's undefined or zero...y/x = Aw, geez, I don't even know how to go about this one...

    Write an equation of a line that passes through the points (2,3) and (2,-6).

    slope = -9/0

    I have two points...so, what I would do is...hm, would graphing them help me or not?
     
    Last edited: Nov 2, 2005
  2. jcsd
  3. Nov 2, 2005 #2

    verty

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    Your answers are correct. So maths can be simple...
     
  4. Nov 2, 2005 #3
    Thanks.:smile:

    I suppose I was a bit late with my edit...:rofl:

    Write an equation of a line that passes through (9,-5) and (3,-5).

    The slope is 0/-6, right? Does that make it undefined or 0? I can't tell the difference. What if the answer was -6/0? Which would that be?

    As for writing the equation, it would be x or y, whichever it is according to whether it's undefined or zero...y/x = Aw, geez, I don't even know how to go about this one...*Pulls out her notes* I can't find anything referring to this type of problem...Method 1: If you are given the equation of the line, put the equation in slope intercept form. Nope, that's not it. Method 2: If you are given the graph of the equation, count the change in y and the change in x on the graph paper to determine the slope. Nope, not right either. Method 3: Nope, that only shows how to find the slope (I used method three for this one...) but it doesn't show what to do next...

    Write an equation of a line that passes through the points (2,3) and (2,-6).

    slope = -9/0

    I have two points...so, what I would do is...hm, would graphing them help me or not?
     
  5. Nov 2, 2005 #4

    verty

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    Look at the points. What do you see?
     
  6. Nov 2, 2005 #5
    I don't know...I don't know what I'm supposed to be seeing. I've looked at them already so if I wasn't seeing it before I'm not seeing it now.:shy: :rofl:
     
  7. Nov 2, 2005 #6
    Never mind, got it. ^_^
     
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