# Limits at infinity

1. Feb 26, 2008

### EvilBunny

lim as x goes closer to minus infinity.

x^4 + x^5

now visibly the answer is minus infinity since the equation are simple. But aside from saying x^5 is bigger then x^4 could there be anything else to do ?

2. Feb 26, 2008

### sutupidmath

why would the answer be minus infinity???

3. Feb 26, 2008

### sutupidmath

well as the expression is written right now
you cannot tell what the limit is since you will end up with infinity-infinity, which is an intermediate form, or how do u call it in english! But hopefully there is sth we can do to avoid this, here:

x^4+x^5=x^4(x+1) so now infinity*(-infinity)=-infinity