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Line inclination

  1. Nov 17, 2003 #1
    (I don't study math in English so I'm not sure what the exact terms are... please bear with me. :))

    If you have this line:
    y = mx + n
    m is the inclination of the line, right? And I have this equation to find m:
    2m + 1 = 2m + 4 (I'm finding a line between two other lines that divides the angle in half)
    Obviously no m can solve that equation - this means that the line is reall of the form:
    x = [a number]

    Am I correct?
  2. jcsd
  3. Nov 17, 2003 #2


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    Staff Emeritus
    Science Advisor
    Gold Member

    Knowing only what you've written here, my best guess is that you're correct. What was the entire problem?

    P.S. we would call m the slope of the line.
  4. Nov 17, 2003 #3
    The whole problem was this:

    You have a triangle ABC, with BC on the line:
    3x - 4y + 37 = 0 (BC)
    And then you also have the equations for the two lines that divide the angles B and C of the triangle:
    2x - y + 3 = 0 (BE)
    x + 7y - 4 = 0 (CF)

    I solved it by finding the slope of both AB and AC, and then finding B and C, and then finding the equations of AB and AC, and finally finding the coordinates of A.

    To find m (slope of AB) I did this: (based on the given that the angle between AB and BE is the same as the angle between BE and BC)
    (2 - m) / (1 + 2m) = (3/4 - 2) / (1 + 6/4) = -1/2
    -4 + 2m = 1 + 2m
    -4 = 1

    And from this I deduced that the line AB is perpendicular (sp?) to the X axis. I found B to be (5, 13) and since it is on the AB line I figured that AB was x = 5.

    Thanks for the help. :-)
    Last edited: Nov 17, 2003
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