# [SOLVED] inverse of a function

• Feb 18th 2009, 08:27 PM
roachbeats
[SOLVED] inverse of a function
I think that I did this right but I am unsure
2x-3/x+1
=x-3/x+2
• Feb 18th 2009, 08:47 PM
mollymcf2009
Quote:

Originally Posted by roachbeats
I think that I did this right but I am unsure
2x-3/x+1
=x-3/x+2

You are close, you just have sign errors:

Starting with

$y = \frac{2x-3}{x+1}$

Switch your x & y terms:

$x = \frac{2y-3}{y+1}$

x(y+1) = 2y-3

xy - 2y = -x-3

y(x-2) = -x-3

$y = \frac{-x-3}{x-2}$