Results 1 to 3 of 3

Math Help - line joining

  1. #1
    Junior Member
    Joined
    May 2010
    Posts
    28

    line joining

    what is the line joining (-4,1) and (-2,5)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,697
    Thanks
    1513
    Quote Originally Posted by alysha230893 View Post
    what is the line joining (-4,1) and (-2,5)
    Here you have

    (x_1, y_1) = (-4, 1)

    and

    (x_2, y_2) = (-2, 5).



    The equation of the line is

    y - y_1 = m(x - x_1), where m = \frac{y_2 - y_1}{x_2 - x_1}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Feb 2010
    Posts
    5
    Firstly, you need to find the gradient, in the form

    y=mx+c

    The formula for gradient is

    (y1-y2)/(x1-x2)

    so

    (5-1)/(-2--4) = 4/2 = 2

    So you know that the line is y=2x+c

    Now substitute one of the points into the equation

    1=2(-4)+c

    1=-8+c

    so 9 = c

    So the equation of the line is

    y=2x+9
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: October 16th 2011, 07:55 PM
  2. [SOLVED] Find the equation of the line joining (0-3), (-5,0)
    Posted in the Pre-Calculus Forum
    Replies: 6
    Last Post: September 26th 2011, 09:50 AM
  3. joining of two measures
    Posted in the Differential Geometry Forum
    Replies: 0
    Last Post: September 8th 2010, 12:22 PM
  4. Tricky grid joining problem
    Posted in the Advanced Math Topics Forum
    Replies: 1
    Last Post: April 9th 2010, 03:49 PM
  5. MatLab - Joining The Dots.
    Posted in the Math Software Forum
    Replies: 2
    Last Post: February 17th 2009, 06:10 AM

Search Tags


/mathhelpforum @mathhelpforum