Results 1 to 3 of 3

Math Help - image of a point

  1. #1
    Newbie
    Joined
    Mar 2009
    From
    Lucknow
    Posts
    13

    Exclamation image of a point

    can u help me :
    1... image of the point P(1,5) with respect to the line 4x+3y+6=0.
    2... the equation of the line segment AB is y=x. If A and B lie on the same side of the mirror 2x-y=1. then wat is the equation of the image?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Mar 2007
    Posts
    1,240

    Talking

    Quote Originally Posted by Gaurav View Post
    1... image of the point P(1,5) with respect to the line 4x+3y+6=0.
    Is "the image of a point with respect to a line" the "location of the point after reflection across the line"?

    If so, then find the slope of the line 4x + 3y + 6 = 0 (by solving for "y=" and then reading off the value of "m"). Find the equation of the line through (1, 5) and having a slope that is perpendicular to the original line.

    Now that you have two line equations, you have a system of equations. Solve this system to find where the two lines cross. The intersection point is the closes point on the line to the point (1, 5).

    Plug the original point and the intersection point into the Midpoint Formula, using (x, y) as the point equidistant on the other side, and solve for the coordinates of the image (mirrored) point.

    Quote Originally Posted by Gaurav View Post
    2... the equation of the line segment AB is y=x. If A and B lie on the same side of the mirror 2x-y=1. then wat is the equation of the image?
    You might find it simplest to mirror a few points from y = 2x - 1 first (since you'll just be swapping the x- and y-values for the mirrored line), and then pick two of those points and find the equation of the line through them.

    If you get stuck, please reply showing all of your steps and reasoning so far. Thank you!
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Mar 2009
    From
    Lucknow
    Posts
    13
    thanks. got u.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Pre-Image / Image proof
    Posted in the Differential Geometry Forum
    Replies: 1
    Last Post: March 9th 2012, 03:30 AM
  2. Replies: 0
    Last Post: October 10th 2011, 10:43 PM
  3. Coordinates of image of point
    Posted in the Geometry Forum
    Replies: 8
    Last Post: April 5th 2011, 07:55 AM
  4. Replies: 1
    Last Post: October 27th 2009, 01:09 AM
  5. Image of a point under various transformations
    Posted in the Geometry Forum
    Replies: 1
    Last Post: May 8th 2009, 07:17 PM

Search Tags


/mathhelpforum @mathhelpforum