Rearranging issue

• Sep 30th 2008, 12:36 AM
Naur
Rearranging issue
Like always, I swear I'm right, but I'm obviously not. I'm trying to find the inverse of the function given, by swapping y with x, and then rearranging to make y the subject again.
But apparently I'm wrong. They don't have a negative on their 3, whereas I do. What am I doing wrong?

Ps. Sorry about the mess. I'm pretty sure it's readable, but it turns out my scanner doesn't like it when I write on both sides of the page.
• Sep 30th 2008, 02:01 AM
mr fantastic
Quote:

Originally Posted by Naur
Like always, I swear I'm right, but I'm obviously not. I'm trying to find the inverse of the function given, by swapping y with x, and then rearranging to make y the subject again.
But apparently I'm wrong. They don't have a negative on their 3, whereas I do. What am I doing wrong?

Ps. Sorry about the mess. I'm pretty sure it's readable, but it turns out my scanner doesn't like it when I write on both sides of the page.

$-\ln \left(\frac{x-8}{-3} \right) = - \ln \left( \frac{8-x}{3}\right) = \ln \left( \frac{3}{8-x}\right)$.
• Sep 30th 2008, 04:55 AM
Naur
I see. That's the step I didn't pick up on. Thanks.