# Thread: Need help with inverse relations.

1. ## 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!

2. Originally Posted by lilmszbrina
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 $y=2x^2 +x-3$

3. oh, typo i wasnt paying attention, but you are right.

4. In your PM you are now saying the equation is

$y=x^2 +x-3$

or is it?

$y=2x^2 +x-3$

5. okay its the second one. im just being really careless sorry.

6. You need to swap x and y, then solve for y. To do this you need to complete the square.