# Math Help - How do I find the inverse of a rational function?

1. ## How do I find the inverse of a rational function?

How do I find the inverse of the following rational function?:

y = -4(x-2)/(x+1)

Any help would be GREATLY appreciated!

2. Originally Posted by s3a
How do I find the inverse of the following rational function?:

y = -4(x-2)/(x+1)

Any help would be GREATLY appreciated!
switch x and y

$x = \frac {-4(y - 2)}{y + 1}$

now solve for y, the resulting function is your inverse function

3. My problem is when it comes to solving for y.

4. $x = \frac {-4(y - 2)}{y + 1}$

$x(y + 1) = -4(y - 2)$

$xy + x = -4y + 8$

$xy + 4y = -x + 8$

$y(x + 4) = -x + 8$

$y = \frac{-x + 8}{x + 4}$

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