# Math Help - How do I find the inverse?

1. ## How do I find the inverse?

Problem is find the inverse of $f(x) = x^2-2x+4$

2. Originally Posted by Henryt999
Problem is find the inverse of $f(x) = x^2-2x+4$
The short answer is: you can't.
There must be some restrictions. What are they?

3. ## ops

Originally Posted by Plato
The short answer is: you can't.
There must be some restrictions. What are they?
Ops, sorry it said: $f:[1,\infty)\rightarrow R, f(x) = x^2 -2x +4$

4. Set $x = y^2 - 2y + 4$

and solve for y.

5. ## Thats it?

Originally Posted by icemanfan
Set $x = y^2 - 2y + 4$

and solve for y.
Yes, thanks, that I understand I get
$x-4 = y(y-2)$
And now what?

6. Originally Posted by Henryt999
Yes, thanks, that I understand I get
$x-4 = y(y-2)$
And now what?
Try this:

$x = y^2 - 2y + 4$

$x = y^2 - 2y + 1 + 3$

$x = (y - 1)^2 + 3$

etc.