Results 1 to 6 of 6

Math Help - Need help with inverse relations.

  1. #1
    Newbie
    Joined
    Sep 2009
    Posts
    3

    Need help with inverse relations.

    My teacher gave us this equation. y=2y^2 +x-3. The assignment was to find the inverse of the equation and determine whether it is a functiion or not.

    I know it will be a function, but I'm not sure how to find the answer, which she gave to us. It is:

    y= -1 [plus or minus] squareroot( 8x=25)
    -------------------------------------
    4

    if you didnt understand that, in plain words it is y equals negative one plus or minus the square root of 8x plus 25. and then all that divided by 4. PLEASE HELP!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,234
    Thanks
    27
    Quote Originally Posted by lilmszbrina View Post
    My teacher gave us this equation. y=2y^2 +x-3.

    Are you sure the equation is y=2y^2 +x-3 . I would suggest it is probably y=2x^2 +x-3
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Sep 2009
    Posts
    3
    oh, typo i wasnt paying attention, but you are right.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,234
    Thanks
    27
    In your PM you are now saying the equation is

     y=x^2 +x-3

    or is it?

     y=2x^2 +x-3
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Sep 2009
    Posts
    3
    okay its the second one. im just being really careless sorry.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,234
    Thanks
    27
    You need to swap x and y, then solve for y. To do this you need to complete the square.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Relations and Functions - Inverse Relations Question
    Posted in the Discrete Math Forum
    Replies: 1
    Last Post: November 13th 2011, 12:20 PM
  2. Replies: 1
    Last Post: September 19th 2011, 01:09 PM
  3. Inverse circular relations problems
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: April 23rd 2010, 10:34 PM
  4. inverse trig values and finding inverse
    Posted in the Trigonometry Forum
    Replies: 4
    Last Post: April 6th 2009, 12:04 AM
  5. Inverse Relations
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: February 11th 2009, 05:48 PM

Search Tags


/mathhelpforum @mathhelpforum