Results 1 to 6 of 6

Math Help - Deriving the equation

  1. #1
    Member
    Joined
    Nov 2006
    From
    chicago
    Posts
    156

    Deriving the equation

    Derive the equation (general form) of all points that are equidistant from the point F(-6,3) and the line y = -5.

    Thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Global Moderator

    Joined
    Nov 2005
    From
    New York City
    Posts
    10,616
    Thanks
    10
    Quote Originally Posted by Mr_Green View Post
    Derive the equation (general form) of all points that are equidistant from the point F(-6,3) and the line y = -5.

    Thanks
    Let (x,y) be such a point. Then what is that distance from this point to (6,3)? What is the distance from this point to y=-5? Now equate these two quantities and you have your equation.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Nov 2006
    From
    chicago
    Posts
    156
    sqrt[(x+6)^2 + (y-3)^2] = sqrt[(0^2) + (y+5)^2]

    square both sides

    x^2 + 12x + 36 + y^2 - 6y + 9 = y^2 + 10y +25

    x^2 + 12x -16y -11 = 0


    Is this correct?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by Mr_Green View Post
    sqrt[(x+6)^2 + (y-3)^2] = sqrt[(0^2) + (y+5)^2]

    square both sides

    x^2 + 12x + 36 + y^2 - 6y + 9 = y^2 + 10y +25

    x^2 + 12x -16y -11 = 0


    Is this correct?
    the distance of (-6,3) to the line y = -5 is the distance between the points (-6,3) and (-6,-5), you don't really need the formula for this, but you can use it if you want to (we are looking for the shortest distance here, which is a vertical line, so the x's are the same)
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Nov 2006
    From
    chicago
    Posts
    156
    its correct though?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by Mr_Green View Post
    its correct though?
    yes, how you expanded before was correct. it's just that the right side should be a number. namely the square of the number i asked you to calculate
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Help deriving an equation.
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 1st 2012, 08:47 AM
  2. Deriving the equation
    Posted in the Advanced Statistics Forum
    Replies: 5
    Last Post: September 25th 2010, 09:10 PM
  3. Deriving an equation
    Posted in the Algebra Forum
    Replies: 2
    Last Post: March 30th 2010, 03:07 AM
  4. Help deriving an equation
    Posted in the Calculus Forum
    Replies: 3
    Last Post: September 17th 2009, 03:56 PM
  5. Kinematics (Deriving Equation)
    Posted in the Calculus Forum
    Replies: 6
    Last Post: May 31st 2008, 04:29 AM

Search Tags


/mathhelpforum @mathhelpforum