I have f(x) = (x^2+x-2)/(x-1) and g(x) = x+2(adsbygoogle = window.adsbygoogle || []).push({});

Now everyone would agree that f has a domain R\{1} and g has a domain R.

Yet I can write (x^2+x-2)/(x-1) = x+2

So why wouldn't g have a domain R\{1} if I rewrite the expression, and vice versa for f? What mathematical principle is behind this?

**Physics Forums - The Fusion of Science and Community**

# Why aren't these functions the same?

Know someone interested in this topic? Share a link to this question via email,
Google+,
Twitter, or
Facebook

- Similar discussions for: Why aren't these functions the same?

Loading...

**Physics Forums - The Fusion of Science and Community**